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URLhttps://en.wikipedia.org/wiki/Sagittarius_A*
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This article is about the black hole. For the surrounding region, see Sagittarius A . Sagittarius A* Sagittarius A* imaged by the Event Horizon Telescope in 2017, released in 2022 Observation data Epoch J2000        Equinox J2000 Constellation Sagittarius Right ascension 17 h 45 m 40.0409 s Declination −29° 0â€Č 28.118″ [ 1 ] Details Mass 8.54 × 10 36  kg 4.297 × 10 6 [ 2 ]   M ☉ Astrometry Distance 26 996 ± 33 [ 2 ]   ly ( 8277 ± 9 [ 2 ]   pc ) Database references SIMBAD data Sagittarius A* , abbreviated as Sgr A* ( SADGE - AY -star [ 3 ] ), is the supermassive black hole [ 4 ] [ 5 ] [ 6 ] at the Galactic Center of the Milky Way . Viewed from Earth, it is located near the border of the constellations Sagittarius and Scorpius , about 5.6° south of the ecliptic , [ 7 ] visually close to the Butterfly Cluster (M6) and Lambda Scorpii . Sagittarius A* is a bright and very compact astronomical radio source . In May 2022, astronomers released the first image of the accretion disk around the event horizon of Sagittarius A*, [ 8 ] using the Event Horizon Telescope , a world-wide network of radio observatories. [ 9 ] This is the second confirmed image of a black hole, after Messier 87's supermassive black hole in 2019. [ 10 ] [ 11 ] The black hole itself is not seen; as light is incapable of escaping the immense gravitational force of a black hole, only nearby objects whose behavior is influenced by the black hole can be observed. The observed radio and infrared energy emanates from gas and dust heated to millions of degrees while falling into the black hole. [ 12 ] Sgr A* was discovered in 1974 by Bruce Balick and Robert L. Brown, [ 13 ] [ 14 ] and the asterisk * was assigned in 1982 by Brown, [ 15 ] who understood that the strongest radio emission from the center of the galaxy appeared to be due to a compact non-thermal radio object embedded in a larger, and much brighter, radio source, Sagittarius A (Sgr A). The observation of several stars orbiting Sagittarius A*, particularly star S2 , have been used to determine the mass and upper limits on the radius of the object. Based on the mass and the precise radius limits obtained, astronomers concluded that Sagittarius A* was the central supermassive black hole of the Milky Way galaxy. [ 16 ] The current best estimate of its mass is 4.297 ± 0.012 million solar masses . [ 2 ] Reinhard Genzel and Andrea Ghez were each awarded a quarter share in the 2020 Nobel Prize in Physics for their discovery that Sagittarius A* is a supermassive compact object, for which a black hole was the only explanation. Sir Roger Penrose received the other half "for the discovery that black hole formation is a robust prediction of the general theory of relativity ". [ 17 ] Observation and description [ edit ] Sagittarius A* in the constellation of Sagittarius. The black hole is marked with a red circle within the constellation of Sagittarius (The Archer). This map shows most of the stars visible to the unaided eye under good conditions. Size comparison between Sagittarius A* and M87* . The diameter of Sagittarius A* is smaller than the orbit of Mercury . On May 12, 2022, the first image of Sagittarius A* was released by the Event Horizon Telescope Collaboration . The image, which is based on radio interferometer data taken in 2017, confirms that the object contains a black hole. This is the second image of a black hole, [ 10 ] [ 18 ] and took five years of calculations to process. [ 19 ] The data were collected by eight radio observatories at six geographical sites. Radio images are produced from data by aperture synthesis , usually from night-long observations of stable sources. The radio emission from Sgr A* varies on the order of minutes, complicating the analysis. [ 20 ] Their result gives an overall angular size for the source of 51.8 ± 2.3  ÎŒas . [ 18 ] At a distance of 26,000 light-years (8,000 parsecs ), this yields a diameter of 51.8 million kilometres (32.2 million miles). [ a ] For comparison, Earth is 150 million kilometres (1.0 astronomical unit ; 93 million miles ) from the Sun , and Mercury is 46 million km (0.31 AU; 29 million mi) from the Sun at perihelion . The proper motion of Sgr A* is approximately −2.70  mas per year for the right ascension and −5.6 mas per year for the declination . [ 21 ] [ 22 ] [ 23 ] The telescope's measurement of these black holes tested Einstein's theory of relativity more rigorously than has previously been done, and the results match perfectly. [ 11 ] In 2019, measurements made with the High-resolution Airborne Wideband Camera-Plus (HAWC+) mounted in the SOFIA aircraft [ 24 ] revealed that magnetic fields cause the surrounding ring of gas and dust, temperatures of which range from −280 to 17,500 °F (99.8 to 9,977.6 K; −173.3 to 9,704.4 °C), [ 25 ] to flow into an orbit around Sagittarius A*, keeping black hole emissions low. [ 26 ] Astronomers have been unable to observe Sgr A* in the Visible spectrum because of the effect of 25 magnitudes of extinction (absorption and scattering) by dust and gas between the source and Earth. [ 27 ] In April 1933, Karl Jansky , considered one of the fathers of radio astronomy, discovered that a radio signal was coming from a location in the direction of the constellation of Sagittarius, towards the center of the Milky Way. [ 28 ] The radio source later became known as Sagittarius A . His observations did not extend quite as far south as we now know to be the Galactic Center. [ 29 ] Observations by Jack Piddington and Harry Minnett using the CSIRO radio telescope at Potts Hill Reservoir , in Sydney discovered a discrete and bright "Sagittarius-Scorpius" radio source, [ 30 ] which after further observation with the 80-foot (24-metre) CSIRO radio telescope at Dover Heights was identified in a letter to Nature as the probable Galactic Center. [ 31 ] Later observations showed that Sagittarius A actually consists of several overlapping sub-components; a bright and very compact component, Sgr A*, was discovered on February 13 and 15, 1974, by Balick and Robert L. Brown using the baseline interferometer of the National Radio Astronomy Observatory . [ 13 ] [ 14 ] The name Sgr A* was coined by Brown in a 1982 paper because the radio source was "exciting", and excited states of atoms are denoted with asterisks. [ 32 ] [ 33 ] Since the 1980s, it has been evident that the central component of Sgr A* is likely a black hole. In 1994, infrared and sub-millimetre spectroscopy studies by a Berkeley team involving Nobel Laureate Charles H. Townes and future Nobel Prize Winner Reinhard Genzel showed that the mass of Sgr A* was tightly concentrated and on the order of 3 million Suns. [ 34 ] On October 16, 2002, an international team led by Reinhard Genzel at the Max Planck Institute for Extraterrestrial Physics reported the observation of the motion of the star S2 near Sagittarius A* throughout a period of ten years. According to the team's analysis, the data ruled out the possibility that Sgr A* contains a cluster of dark stellar objects or a mass of degenerate fermions , strengthening the evidence for a massive black hole. The observations of S2 used near-infrared (NIR) interferometry (in the Ks-band, i.e. 2.1  ÎŒm ) because of reduced interstellar extinction in this band. SiO masers were used to align NIR images with radio observations, as they can be observed in both NIR and radio bands. The rapid motion of S2 (and other nearby stars) easily stood out against slower-moving stars along the line-of-sight so these could be subtracted from the images. [ 35 ] [ 36 ] Dusty cloud G2 passes the supermassive black hole at the center of the Milky Way. [ 37 ] Composition of images taken at different times to show motion; colored blue when approaching the viewer, red when receding; time is left to right. Red cross marks the black hole. The VLBI radio observations of Sagittarius A* could also be aligned centrally with the NIR images, so the focus of S2's elliptical orbit was found to coincide with the position of Sagittarius A*. From examining the Keplerian orbit of S2, they determined the mass of Sagittarius A* to be 4.1 ± 0.6 million solar masses , confined in a volume with a radius no more than 17 light-hours (120  AU  [18  billion   km ; 11 billion  mi ]). [ 38 ] Later observations of the star S14 showed the mass of the object to be about 4.1 million solar masses within a volume with radius no larger than 6.25 light-hours (45 AU [6.7 billion km; 4.2 billion mi]). [ 39 ] S175 passed within a similar distance. [ 40 ] For comparison, the Schwarzschild radius is 0.08 AU (12 million km; 7.4 million mi). They also determined the distance from Earth to the Galactic Center (the rotational center of the Milky Way), which is important in calibrating astronomical distance scales, as 8,000 ± 600 parsecs (30,000 ± 2,000 light-years ). In November 2004, a team of astronomers reported the discovery of a potential intermediate-mass black hole , referred to as GCIRS 13E , orbiting 3 light-years from Sagittarius A*. This black hole of 1,300 solar masses is within a cluster of seven stars. This observation may add support to the idea that supermassive black holes grow by absorbing nearby smaller black holes and stars. [ citation needed ] After monitoring stellar orbits around Sagittarius A* for 16 years, Gillessen et al. estimated the object's mass at 4.31 ± 0.38 million solar masses. The result was announced in 2008 and published in The Astrophysical Journal in 2009. [ 41 ] Reinhard Genzel , team leader of the research, said the study has delivered "what is now considered to be the best empirical evidence that supermassive black holes do really exist. The stellar orbits in the Galactic Center show that the central mass concentration of four million solar masses must be a black hole, beyond any reasonable doubt." [ 42 ] On January 5, 2015, NASA reported observing an X-ray flare 400 times brighter than usual, a record-breaker, from Sgr A*. The unusual event may have been caused by the breaking apart of an asteroid falling into the black hole or by the entanglement of magnetic field lines within gas flowing into Sgr A*, according to astronomers. [ 43 ] On 13 May 2019, astronomers using the Keck Observatory witnessed a sudden brightening of Sgr A*, which became 75 times brighter than usual, suggesting that the supermassive black hole may have encountered another object. [ 44 ] In June 2023, unexplained filaments of radio energy were found associated with Sagittarius A*. [ 45 ] ALMA observations of molecular-hydrogen-rich gas clouds, with the area around Sagittarius A* circled [ 46 ] An unusually bright X-ray flare from Sgr A* was detected in 2013. [ 43 ] Supernova remnant ejecta producing planet-forming material seen in radio and X-ray Supernova remnant ejecta producing planet-forming material seen in infrared and X-ray NuSTAR has captured these first, focused views of the supermassive black hole at the heart of the Milky Way in high-energy X-rays. In a paper published on October 31, 2018, the discovery of conclusive evidence that Sagittarius A* is a black hole was announced. Using the GRAVITY interferometer and the four telescopes of the Very Large Telescope (VLT) to create a virtual telescope 130 metres (430 feet) in diameter, astronomers detected clumps of gas moving at about 30% of the speed of light. Emission from highly energetic electrons very close to the black hole was visible as three prominent bright flares. These exactly match theoretical predictions for hot spots orbiting close to a black hole of four million solar masses. The flares are thought to originate from magnetic interactions in the very hot gas orbiting very close to Sagittarius A*. [ 12 ] [ 47 ] In July 2018, it was reported that S2 orbiting Sgr A* had been recorded at 7,650 km/s (17.1 million mph), or 2.55% the speed of light , leading up to the pericenter approach, in May 2018, at about 120  AU (18  billion   km ; 11 billion  mi ) (approximately 1,400 Schwarzschild radii ) from Sgr A*. At that close distance to the black hole, Einstein 's theory of general relativity predicts that S2 would show a discernible gravitational redshift in addition to the usual velocity redshift. The gravitational redshift was detected, in agreement with the general relativity prediction within the 10 percent measurement precision. [ 48 ] [ 49 ] The Sagittarius A* radio emissions are not centered on the black hole, but arise from a bright spot in the region around the black hole, close to the event horizon , possibly in the accretion disc , or a relativistic jet of material ejected from the disc. [ 50 ] If the apparent position of Sagittarius A* were exactly centered on the black hole, it would be possible to see it magnified beyond its size, because of gravitational lensing of the black hole. According to general relativity , this would result in a ring-like structure, which has a diameter about 5.2 times the black hole's Schwarzschild radius (10 ÎŒas). For a black hole of around 4 million solar masses, this corresponds to a size of approximately 52  ÎŒas , which is consistent with the observed overall size of about 50 Όas, [ 50 ] the size (apparent diameter) of the black hole Sgr A* itself being 20 ÎŒas. Lower resolution observations revealed that the radio source of Sagittarius A* is symmetrical. [ 51 ] Simulations of alternative theories of gravity depict results that may be difficult to distinguish from GR. [ 52 ] A 2018 paper predicted an image of Sagittarius A* that is in agreement with observations. In particular, it explains the small angular size and the symmetrical morphology of the source. [ 53 ] The mass of Sagittarius A* has been estimated in two different ways: Two groups—in Germany and the U.S.—monitored the orbits of individual stars very near to the black hole and used Kepler's laws to infer the enclosed mass. The German group found a mass of 4.31 ± 0.38 million solar masses, [ 41 ] whereas the American group found 4.1 ± 0.6 million solar masses. [ 39 ] Given that this mass is confined inside a 44-million-kilometre-diameter sphere, this yields a density ten times higher than previous estimates. [ citation needed ] More recently, measurement of the proper motions of a sample of several thousand stars within approximately one parsec from the black hole, combined with a statistical technique , has yielded both an estimate of the black hole's mass at 3.6 +0.2 −0.4 × 10 6 M ☉ , plus a distributed mass in the central parsec amounting to (1 ± 0.5) × 10 6 M ☉ . [ 54 ] The latter is thought to be composed of stars and stellar remnants . [ citation needed ] Magnetar found very close to the supermassive black hole , Sagittarius A*, at the center of the Milky Way galaxy The comparatively small mass of this supermassive black hole , along with the low luminosity of the radio and infrared emission lines, imply that the Milky Way is not a Seyfert galaxy . [ 27 ] Ultimately, what is seen is not the black hole itself, but observations that are consistent only if there is a black hole present near Sgr A*. In the case of such a black hole, the observed radio and infrared energy emanates from gas and dust heated to millions of degrees while falling into the black hole. [ 12 ] The black hole itself is thought to emit only Hawking radiation at a negligible temperature, on the order of 10 −14 kelvin . [ citation needed ] The European Space Agency 's gamma-ray observatory INTEGRAL observed gamma rays interacting with the nearby giant molecular cloud Sagittarius B2 , causing X-ray emission from the cloud. The total luminosity from this outburst ( L ≈1,5 × 10 39 erg/s) is estimated to be a million times stronger than the current output from Sgr A* and is comparable with a typical active galactic nucleus . [ 55 ] [ 56 ] In 2011 this conclusion was supported by Japanese astronomers observing the Milky Way's center with the Suzaku satellite. [ 57 ] In July 2019, astronomers reported finding a star, S5-HVS1 , traveling 1,755 km/s (3.93 million mph) or 0.006 c . The star is in the Grus (or Crane) constellation in the southern sky, and about 29,000 light-years from Earth, and may have been propelled out of the Milky Way galaxy after interacting with Sagittarius A*. [ 58 ] [ 59 ] Several values [ 60 ] [ 61 ] have been given for its spin parameter ; some examples are Fragione & Loeb (2020) [ 62 ] , Belanger et al. (2006) , [ 63 ] Meyer et al. (2006) , [ 64 ] Genzel et al. (2003) , [ 65 ] Daly (2019) , [ 66 ] and Daly et al. (2023) . [ 61 ] Daly et al. (2023) also found that the ratio of the black hole rotational mass component to the irreducible mass component of Sgr A* is , which indicates that the black hole is rotating with an angular velocity that is of the maximum possible value, set by the speed of light. [ 61 ] [ 67 ] Inferred orbits of six stars around supermassive black hole candidate Sagittarius A* at the Milky Way's center [ 68 ] Stars moving around Sagittarius A*, 20-year timelapse, ending in 2018 [ 69 ] [ 70 ] Stars moving around Sagittarius A* as seen in 2021 [ 71 ] [ 72 ] [ 73 ] There are a number of stars in close orbit around Sagittarius A*, which are collectively known as "S stars". [ 74 ] These stars are observed primarily in K band infrared wavelengths, as interstellar dust drastically limits visibility in visible wavelengths. This is a rapidly changing field—in 2011, the orbits of the most prominent stars then known were plotted in the diagram at left, showing a comparison between their orbits and various orbits in the Solar System . [ 70 ] Since then, S62 was thought to approach even more closely than those stars, [ 75 ] but later observations of the star have found this not to be the case. [ 76 ] The high velocities and close approaches to the supermassive black hole makes these stars useful to establish limits on the physical dimensions of Sagittarius A*, as well as to observe general relativity associated effects like periapse shift of their orbits. An active watch is maintained for the possibility of stars approaching the event horizon close enough to be disrupted, but none of these stars are expected to suffer that fate. As of 2020 , S4714 is the current record holder of closest approach to Sagittarius A*, at about 12.6 AU (1.88 billion km), almost as close as Saturn gets to the Sun, traveling at about 8% of the speed of light. These figures given are approximate, the formal uncertainties being 12.6 ± 9.3 AU and 23,928 ± 8,840 km/s . Its orbital period is 12 years, but an extreme eccentricity of 0.985 gives it the close approach and high velocity. [ 77 ] An excerpt from a table of this cluster (see Sagittarius A* cluster ), featuring the most prominent members. In the below table, id1 is the star's name in the Gillessen catalog and id2 in the catalog of the University of California, Los Angeles. a , e , i , Ω and ω are standard orbital elements , with a measured in arcseconds . Tp is the epoch of pericenter passage, P is the orbital period in years and Kmag is the infrared K-band apparent magnitude of the star. q and v are the pericenter distance in AU and pericenter speed in percent of the speed of light . [ 78 ] id1 id2 a e i (°) Ω (°) ω (°) Tp (yr) P (yr) Kmag q (AU) v (%c) S1 S0-1 0.5950 0.5560 119.14 342.04 122.30 2001.800 166.0 14.70 2160.7 0.55 S2 S0-2 0.1251 0.8843 133.91 228.07 66.25 2018.379 16.1 13.95 118.4 2.56 S8 S0-4 0.4047 0.8031 74.37 315.43 346.70 1983.640 92.9 14.50 651.7 1.07 S12 S0-19 0.2987 0.8883 33.56 230.10 317.90 1995.590 58.9 15.50 272.9 1.69 S13 S0-20 0.2641 0.4250 24.70 74.50 245.20 2004.860 49.0 15.80 1242.0 0.69 S14 S0-16 0.2863 0.9761 100.59 226.38 334.59 2000.120 55.3 15.70 56.0 3.83 S4714 0.102 0.985 127.7 129.28 357.25 2017.29 12.0 17.7 12.6 8.0 Discovery of G2 gas cloud on an accretion course [ edit ] First noticed as something unusual in images of the center of the Milky Way in 2002, [ 79 ] the gas cloud G2, which has a mass about three times that of Earth, was confirmed to be likely on a course taking it into the accretion zone of Sgr A* in a paper published in Nature in 2012. [ 80 ] Predictions of its orbit suggested it would make its closest approach to the black hole (a perinigricon ) in early 2014, when the cloud was at a distance of just over 3,000 times the radius of the event horizon (or ≈260 AU, 36 light-hours) from the black hole. G2 has been observed to be disrupting since 2009, [ 80 ] and was predicted by some to be completely destroyed by the encounter, which could have led to a significant brightening of X-ray and other emission from the black hole. Other astronomers suggested the gas cloud could be hiding a dim star, or a binary star merger product, which would hold it together against the tidal forces of Sgr A*, allowing the ensemble to pass by without any effect. [ 81 ] In addition to the tidal effects on the cloud itself, it was proposed in May 2013 [ 82 ] that, prior to its perinigricon, G2 might experience multiple close encounters with members of the black-hole and neutron-star populations thought to orbit near the Galactic Center, offering some insight to the region surrounding the supermassive black hole at the center of the Milky Way. [ 83 ] The average rate of accretion onto Sgr A* is unusually small for a black hole of its mass [ 84 ] and is only detectable because it is so close to Earth. It was thought that the passage of G2 in 2013 might offer astronomers the chance to learn much more about how material accretes onto supermassive black holes. Several astronomical facilities observed this closest approach, with observations confirmed with Chandra , XMM , VLA , INTEGRAL , Swift , Fermi and requested at VLT and Keck . [ 85 ] Simulations of the passage were made before it happened by groups at ESO [ 86 ] and Lawrence Livermore National Laboratory (LLNL). [ 87 ] As the cloud approached the black hole, Daryl Haggard said, "It's exciting to have something that feels more like an experiment", and hoped that the interaction would produce effects that would provide new information and insights. [ 88 ] Nothing was observed during and after the closest approach of the cloud to the black hole, which was described as a lack of "fireworks" and a "flop". [ 89 ] Astronomers from the UCLA Galactic Center Group published observations obtained on March 19 and 20, 2014, concluding that G2 was still intact (in contrast to predictions for a simple gas cloud hypothesis) and that the cloud was likely to have a central star. [ 81 ] An analysis published on July 21, 2014, based on observations by the ESO 's Very Large Telescope in Chile, concluded alternatively that the cloud, rather than being isolated, might be a dense clump within a continuous but thinner stream of matter, and would act as a constant breeze on the disk of matter orbiting the black hole, rather than sudden gusts that would have caused high brightness as they hit, as originally expected. Supporting this hypothesis, G1, a cloud that passed near the black hole 13 years ago, had an orbit almost identical to G2, consistent with both clouds, and a gas tail thought to be trailing G2, all being denser clumps within a large single gas stream. [ 89 ] [ 90 ] Andrea Ghez et al. suggested in 2014 that G2 is not a gas cloud but rather a pair of binary stars that had been orbiting the black hole in tandem and merged into an extremely large star. [ 81 ] [ 91 ] Artist impression of the accretion of gas cloud G2 onto Sgr A*. Credit: ESO [ 92 ] This simulation shows a gas cloud, discovered in 2011, as it passes close to the supermassive black hole at the center of the Milky Way. This video sequence shows the motion of the dusty cloud G2 as it closes in on, and then passes, the supermassive black hole at the center of the Milky Way. Galactic Center GeV excess  – Unexplained gamma rays from the Galactic Center List of nearest known black holes M87* ^ This roughly equates to around 37 times the diameter of the Sun at ~1,400,000 kilometers (~865,000 miles). ^ Reid and Brunthaler 2004 ^ a b c d The GRAVITY collaboration (September 2023). "Polarimetry and astrometry of NIR flares as event horizon scale, dynamical probes for the mass of Sgr A*" . Astronomy & Astrophysics . 677 : L10. arXiv : 2307.11821 . Bibcode : 2023A&A...677L..10G . doi : 10.1051/0004-6361/202347416 . ^ "Astronomers reveal first image of the black hole at the heart of our galaxy" . Event Horizon Telescope . May 12, 2022. Archived from the original on May 12, 2022 . Retrieved May 12, 2022 . ^ Parsons, Jeff (October 31, 2018). "Scientists find proof a supermassive black hole is lurking at the centre of the Milky Way" . Metro . Archived from the original on October 31, 2018 . Retrieved October 31, 2018 . ^ Mosher, Dave (October 31, 2018). "A 'mind-boggling' telescope observation has revealed the point of no return for our galaxy's monster black hole" . The Middletown Press . Business Insider. Archived from the original on October 31, 2018 . Retrieved May 16, 2022 . ^ Plait, Phil (November 7, 2018). "Astronomers See Material Orbiting a Black Hole *Right* at the Edge of Forever" . Bad Astronomy . Syfy Wire. Archived from the original on November 10, 2018 . Retrieved November 12, 2018 . ^ Calculated using Equatorial and Ecliptic Coordinates Archived July 21, 2019, at the Wayback Machine calculator ^ Sutter, Paul (May 20, 2022). "How did astronomers take a picture of our galaxy's supermassive black hole?" . Astronomy Magazine . Retrieved April 16, 2025 . The Event Horizon Telescope (EHT) collaboration released the first ever image of the accretion disk around the Milky Way's supermassive black hole, Sagittarius A* (Sgr A*), on May 12, 2022. ^ Bower, Geoffrey C. (May 2022). "Focus on First Sgr A* Results from the Event Horizon Telescope" . The Astrophysical Journal . Archived from the original on July 19, 2022 . Retrieved May 12, 2022 . ^ a b "Astronomers reveal first image of the black hole at the heart of our galaxy" . eso.org . May 12, 2022. Archived from the original on May 12, 2022 . Retrieved May 12, 2022 . ^ a b Overbye, Dennis (May 12, 2022). "The Milky Way's Black Hole Comes to Light" . The New York Times . ISSN   0362-4331 . Archived from the original on May 12, 2022 . Retrieved May 12, 2022 . ^ a b c Abuter, R.; Amorim, A.; Bauböck, M.; Berger, J. P.; Bonnet, H.; Brandner, W.; ClĂ©net, Y.; CoudĂ© Du Foresto, V.; De Zeeuw, P. T.; Deen, C.; Dexter, J.; Duvert, G.; Eckart, A.; Eisenhauer, F.; Förster Schreiber, N. M. ; Garcia, P.; Gao, F.; Gendron, E.; Genzel, R.; Gillessen, S.; Guajardo, P.; Habibi, M.; Haubois, X.; Henning, T.; Hippler, S.; Horrobin, M.; Huber, A.; JimĂ©nez Rosales, A.; Jocou, L.; et al. (2018). "Detection of orbital motions near the last stable circular orbit of the massive black hole SgrA". Astronomy & Astrophysics . 618 : L10. arXiv : 1810.12641 . Bibcode : 2018A&A...618L..10G . doi : 10.1051/0004-6361/201834294 . S2CID   53613305 . ^ a b Balick, B.; Brown, R. L. (December 1, 1974). "Intense sub-arcsecond structure in the galactic center" . Astrophysical Journal . 194 (1): 265– 270. Bibcode : 1974ApJ...194..265B . doi : 10.1086/153242 . S2CID   121802758 . ^ a b Melia 2007 , p. 7 ^ Brown, Robert L. (November 1, 1982). "Precessing Jets in Sagittarius A: Gas Dynamics in the Central Parsec of the Galaxy" . The Astrophysical Journal . 262 : 110– 119. Bibcode : 1982ApJ...262..110B . doi : 10.1086/160401 . ^ Henderson, Mark (December 9, 2009). "Astronomers confirm black hole at the heart of the Milky Way" . Times Online. Archived from the original on December 16, 2008 . Retrieved June 6, 2019 . ^ "The Nobel Prize in Physics 2020" . October 6, 2020. Archived from the original on April 24, 2021 . Retrieved October 7, 2020 . ^ a b The Event Horizon Telescope Collaboration (May 1, 2022). "First Sagittarius A* Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole in the Center of the Milky Way" . The Astrophysical Journal Letters . 930 (2): L12. arXiv : 2311.08680 . Bibcode : 2022ApJ...930L..12E . doi : 10.3847/2041-8213/ac6674 . eISSN   2041-8213 . hdl : 10261/278882 . ISSN   2041-8205 . S2CID   248744791 . ^ Hensley, Kerry (May 12, 2022). "First Image of the Milky Way's Supermassive Black Hole" . AAS Nova . Archived from the original on August 2, 2022 . Retrieved May 13, 2022 . ^ The Event Horizon Telescope Collaboration (May 1, 2022). "First Sagittarius A* Event Horizon Telescope Results. III. Imaging of the Galactic Center Supermassive Black Hole" . The Astrophysical Journal Letters . 930 (2): L14. arXiv : 2311.09479 . Bibcode : 2022ApJ...930L..14E . doi : 10.3847/2041-8213/ac6429 . eISSN   2041-8213 . ISSN   2041-8205 . S2CID   248744704 . ^ Backer and Sramek 1999 , § 3 ^ "Focus on the First Event Horizon Telescope Results – The Astrophysical Journal Letters – IOPscience" . iopscience.iop.org . Archived from the original on May 14, 2019 . Retrieved April 10, 2019 . ^ Overbye, Dennis (April 10, 2019). "Black Hole Picture Revealed for the First Time" . The New York Times . ISSN   0362-4331 . Archived from the original on May 21, 2019 . Retrieved April 10, 2019 . ^ "HAWC+, the Far-Infrared Camera and Polarimeter for SOFIA" . 2018. Archived from the original on August 3, 2021 . Retrieved August 3, 2021 . ^ "The Milky Way's Monster Black Hole Has a Cool Gas Halo – Literally" . Space.com . June 5, 2019. Archived from the original on June 19, 2019 . Retrieved June 19, 2019 . ^ "Magnetic Fields May Muzzle Milky Way's Monster Black Hole" . Space.com . June 14, 2019. Archived from the original on June 18, 2019 . Retrieved June 19, 2019 . ^ a b Osterbrock and Ferland 2006 , p. 390 ^ "Karl Jansky: The Father of Radio Astronomy" . August 29, 2012. Archived from the original on June 28, 2019 . Retrieved January 27, 2019 . ^ Goss, W. M.; McGee, R. X. (1996). "The Discovery of the Radio Source Sagittarius A (Sgr A)" . The Galactic Center, Astronomical Society of the Pacific Conference Series . 102 : 369. Bibcode : 1996ASPC..102..369G . Archived from the original on March 3, 2021 . Retrieved February 25, 2021 . ^ Piddington, J. H.; Minnett, H. C. (December 1, 1951). "Observations of Galactic Radiation at Frequencies of 1200 and 3000 Mc/s" . Australian Journal of Scientific Research A . 4 (4): 459. Bibcode : 1951AuSRA...4..459P . doi : 10.1071/CH9510459 . Archived from the original on April 13, 2021 . Retrieved February 25, 2021 . ^ McGee, R. X.; Bolton, J. G. (May 1, 1954). "Probable observation of the galactic nucleus at 400 Mc./s" . Nature . 173 (4412): 985– 987. Bibcode : 1954Natur.173..985M . doi : 10.1038/173985b0 . ISSN   0028-0836 . S2CID   4188235 . Archived from the original on January 30, 2022 . Retrieved February 25, 2021 . ^ Goss, W. M.; Brown, Robert L.; Lo, K. Y. (May 6, 2003). "The Discovery of Sgr A*". Astronomische Nachrichten . 324 (1): 497. arXiv : astro-ph/0305074 . Bibcode : 2003ANS...324..497G . doi : 10.1002/asna.200385047 . ^ Brown, R. L. (November 1, 1982). "Precessing jets in Sagittarius A – Gas dynamics in the central parsec of the galaxy" . Astrophysical Journal, Part 1 . 262 : 110– 119. Bibcode : 1982ApJ...262..110B . doi : 10.1086/160401 . ^ Genzel, R; Hollenbach, D; Townes, C H (1994). "The nucleus of our Galaxy". Reports on Progress in Physics . 57 (5): 417– 479. Bibcode : 1994RPPh...57..417G . doi : 10.1088/0034-4885/57/5/001 . ISSN   0034-4885 . S2CID   250900662 . ^ Schödel et al. 2002 ^ Sakai, Shoko; Lu, Jessica R.; Ghez, Andrea; Jia, Siyao; Do, Tuan; Witzel, Gunther; Gautam, Abhimat K.; Hees, Aurelien; Becklin, E.; Matthews, K.; Hosek, M. W. (March 5, 2019). "The Galactic Center: An Improved Astrometric Reference Frame for Stellar Orbits around the Supermassive Black Hole" . The Astrophysical Journal . 873 (1): 65. arXiv : 1901.08685 . Bibcode : 2019ApJ...873...65S . doi : 10.3847/1538-4357/ab0361 . ISSN   1538-4357 . S2CID   119331998 . ^ "Best View Yet of Dusty Cloud Passing Galactic Centre Black Hole" . Archived from the original on April 7, 2015 . Retrieved June 16, 2015 . ^ Ghez et al. (2003) "The First Measurement of Spectral Lines in a Short-Period Star Bound to the Galaxy's Central Black Hole: A Paradox of Youth" Astrophysical Journal 586 L127 ^ a b Ghez, A. M.; et al. (December 2008). "Measuring Distance and Properties of the Milky Way's Central Supermassive Black Hole with Stellar Orbits". Astrophysical Journal . 689 (2): 1044– 1062. arXiv : 0808.2870 . Bibcode : 2008ApJ...689.1044G . doi : 10.1086/592738 . S2CID   18335611 . ^ Gillessen, S.; Plewa, P. M.; Eisenhauer, F.; Sari, R.; Waisberg, I.; Habibi, M.; Pfuhl, O.; George, E.; Dexter, J. (2017). "An Update on Monitoring Stellar Orbits in the Galactic Center" . The Astrophysical Journal . 837 (1): 30. arXiv : 1611.09144 . Bibcode : 2017ApJ...837...30G . doi : 10.3847/1538-4357/aa5c41 . ISSN   0004-637X . S2CID   119087402 . ^ a b Gillessen et al. 2009 ^ O'Neill 2008 ^ a b Chou, Felicia; Anderson, Janet; Watzke, Megan (January 5, 2015). "NASA's Chandra Detects Record-Breaking Outburst from Milky Way's Black Hole" . NASA . Archived from the original on January 6, 2015 . Retrieved January 6, 2015 . ^ "Our Galaxy's Supermassive Black Hole Has Emitted a Mysteriously Bright Flare" . Science Alert . August 12, 2019. Archived from the original on August 12, 2019 . Retrieved August 12, 2019 . ^ Overbye, Dennis (June 8, 2023). "Our Local Black Hole Serves Up an 'Awe Moment' – Filaments of radio energy from Sagittarius A*, the black hole at the center of the Milky Way galaxy, are turning astronomers' heads" . The New York Times . Retrieved June 9, 2023 . {{ cite news }} : CS1 maint: deprecated archival service ( link ) ^ "Cloudlets swarm around our local supermassive black hole" . www.eso.org . Archived from the original on October 22, 2018 . Retrieved October 22, 2018 . ^ "Most Detailed Observations of Material Orbiting close to a Black Hole" . European Southern Observatory (ESO) . Archived from the original on November 1, 2018 . Retrieved November 1, 2018 . ^ Genzel; et al. (July 26, 2018). "Detection of the gravitational redshift in the orbit of the star S2 near the Galactic centre massive black hole" . Astronomy & Astrophysics . 615 : L15. arXiv : 1807.09409 . Bibcode : 2018A&A...615L..15G . doi : 10.1051/0004-6361/201833718 . S2CID   118891445 . Archived from the original on April 4, 2019 . Retrieved July 27, 2018 . ^ "Star spotted speeding near black hole at centre of Milky Way – Chile's Very Large Telescope tracks S2 star as it reaches mind-boggling speeds by supermassive black hole" . The Guardian . July 26, 2017. Archived from the original on April 4, 2019 . Retrieved July 27, 2018 . ^ a b Lu, R.; et al. (2018). "Detection of intrinsic source structure at ~3 Schwarzschild radii with Millimeter-VLBI observations of Sgr A*" . Astrophysical Journal . 859 (1): 60. arXiv : 1805.09223 . doi : 10.3847/1538-4357/aabe2e . S2CID   51917277 . ^ Issaoun, S. (January 18, 2019). "The Size, Shape, and Scattering of Sagittarius A* at 86 GHz: First VLBI with ALMA" . The Astrophysical Journal . 871 (1): 30. arXiv : 1901.06226 . Bibcode : 2019ApJ...871...30I . doi : 10.3847/1538-4357/aaf732 . S2CID   84180473 . ^ Rezzolla, Luciano (April 17, 2018). "Astrophysicists Test Theories of Gravity with Black Hole Shadows" . SciTech Daily . Archived from the original on April 2, 2019 . Retrieved April 2, 2019 . ^ "Revealing the black hole at the heart of the galaxy" . Netherlands Research School for Astronomy. January 22, 2019. Archived from the original on March 18, 2019 . Retrieved April 2, 2019 – via Phys.org . ^ Schödel et al. 2009 ^ "Integral rolls back history of Milky Way's super-massive black hole" . Hubble News Desk. January 28, 2005. Archived from the original on October 16, 2012 . Retrieved October 31, 2007 . ^ Revnivtsev, M. G.; et al. (October 2004). "Hard X-ray view of the past activity of Sgr A$^{\star}$ in a natural Compton mirror". Astronomy & Astrophysics . 425 (3): L49– L52. arXiv : astro-ph/0408190 . Bibcode : 2004A&A...425L..49R . doi : 10.1051/0004-6361:200400064 . ISSN   0004-6361 . S2CID   18872302 . ^ Nobukawa, M.; et al. (September 8, 2011). "New Evidence for High Activity of the Supermassive Black Hole in our Galaxy". The Astrophysical Journal . 739 (2): L52. arXiv : 1109.1950 . Bibcode : 2011ApJ...739L..52N . doi : 10.1088/2041-8205/739/2/L52 . ISSN   2041-8205 . S2CID   119244398 . ^ Overbye, Dennis (November 14, 2019). "A Black Hole Threw a Star Out of the Milky Way Galaxy – So long, S5-HVS1, we hardly knew you" . The New York Times . Archived from the original on November 17, 2019 . Retrieved November 18, 2019 . ^ Koposov, Sergey E; et al. (January 11, 2020). "Discovery of a nearby 1700 km s−1 star ejected from the Milky Way by Sgr A*" . Monthly Notices of the Royal Astronomical Society . 491 (2): 2465– 2480. arXiv : 1907.11725 . doi : 10.1093/mnras/stz3081 . ISSN   0035-8711 . S2CID   198968336 . ^ Eckart, Andreas; Tursunov, A.A.; Zajacek, M.; Parsa, M.; Hosseini, E.; Subroweit, M.; Peissker, F.; Straubmeier, C.; Horrobin, M.; Karas, V. (February 1, 2019). "Mass, Distance, Spin, Charge, and Orientation of the super massive black hole SgrA*" . Proceedings of Science . 342 . Sissa Medialab: 048. doi : 10.22323/1.342.0048 . S2CID   189921901 . ^ a b c Daly, Ruth A; Donahue, Megan; O'Dea, Christopher P; Sebastian, Biny; Haggard, Daryl; Lu, Anan (October 28, 2023). "New black hole spin values for Sagittarius A* obtained with the outflow method" . Monthly Notices of the Royal Astronomical Society . 527 (1): 428– 436. arXiv : 2310.12108 . doi : 10.1093/mnras/stad3228 . ISSN   0035-8711 . ^ Fragione, Giacomo; Loeb, Abraham (October 1, 2020). "An Upper Limit on the Spin of SgrA* Based on Stellar Orbits in Its Vicinity" . The Astrophysical Journal . 901 (2): L32. arXiv : 2008.11734 . Bibcode : 2020ApJ...901L..32F . doi : 10.3847/2041-8213/abb9b4 . ISSN   2041-8213 . ^ BĂ©langer, G; Terrier, R; Jager, O C de; Goldwurm, A; Melia, F (December 1, 2006). "Periodic Modulations in an X-ray Flare from Sagittarius A*" . Journal of Physics: Conference Series . 54 : 420– 426. arXiv : astro-ph/0604337 . Bibcode : 2006JPhCS..54..420B . doi : 10.1088/1742-6596/54/1/066 . ISSN   1742-6588 . S2CID   250670477 . ^ Meyer, L.; Eckart, A.; Schödel, R.; Duschl, W. J.; MuĆŸić, K.; Dovčiak, M.; Karas, V. (December 2006). "Near-infrared polarimetry setting constraints on the orbiting spot model for Sgr A* flares" . Astronomy & Astrophysics . 460 (1): 15– 21. arXiv : astro-ph/0610104 . Bibcode : 2006A&A...460...15M . doi : 10.1051/0004-6361:20065925 . ISSN   0004-6361 . S2CID   15370123 . ^ Genzel, R.; Schödel, R.; Ott, T.; Eckart, A.; Alexander, T.; Lacombe, F.; Rouan, D.; Aschenbach, B. (November 2003). "Near-infrared flares from accreting gas around the supermassive black hole at the Galactic Centre" . Nature . 425 (6961): 934– 937. arXiv : astro-ph/0310821 . Bibcode : 2003Natur.425..934G . doi : 10.1038/nature02065 . ISSN   0028-0836 . PMID   14586462 . S2CID   4325930 . ^ Daly, Ruth A. (November 15, 2019). "Black Hole Spin and Accretion Disk Magnetic Field Strength Estimates for More Than 750 Active Galactic Nuclei and Multiple Galactic Black Holes" . The Astrophysical Journal . 886 (1): 37. arXiv : 1905.11319 . Bibcode : 2019ApJ...886...37D . doi : 10.3847/1538-4357/ab35e6 . ISSN   0004-637X . ^ Daly, Ruth A (October 20, 2022). "Robust supermassive black hole spin mass-energy characteristics: a new method and results" . Monthly Notices of the Royal Astronomical Society . 517 (4): 5144– 5159. arXiv : 2210.07779 . doi : 10.1093/mnras/stac2976 . ISSN   0035-8711 . ^ Eisenhauer, F.; et al. (July 20, 2005). "SINFONI in the Galactic Center: Young Stars and Infrared Flares in the Central Light-Month". The Astrophysical Journal . 628 (1): 246– 259. arXiv : astro-ph/0502129 . Bibcode : 2005ApJ...628..246E . doi : 10.1086/430667 . S2CID   122485461 . ^ "First Successful Test of Einstein's General Relativity Near Supermassive Black Hole – Culmination of 26 years of ESO observations of the heart of the Milky Way" . www.eso.org . Archived from the original on March 8, 2019 . Retrieved December 15, 2021 . ^ a b GRAVITY Collaboration; Abuter, R.; Amorim, A.; Anugu, N.; Bauböck, M.; Benisty, M.; Berger, J. P.; Blind, N.; Bonnet, H.; Brandner, W.; Buron, A. (July 2018). "Detection of the gravitational redshift in the orbit of the star S2 near the Galactic centre massive black hole" . Astronomy & Astrophysics . 615 : L15. arXiv : 1807.09409 . Bibcode : 2018A&A...615L..15G . doi : 10.1051/0004-6361/201833718 . ISSN   0004-6361 . S2CID   118891445 . Archived from the original on July 27, 2020 . Retrieved December 15, 2021 . ^ "Watch stars move around the Milky Way's supermassive black hole in deepest images yet" . www.eso.org . Archived from the original on December 14, 2021 . Retrieved December 15, 2021 . ^ GRAVITY Collaboration; Stadler, J.; Drescher, A. (December 14, 2021). "Deep images of the Galactic center with GRAVITY" . Astronomy & Astrophysics . 657 : A82. arXiv : 2112.07477 . doi : 10.1051/0004-6361/202142459 . ISSN   0004-6361 . S2CID   245131155 . ^ GRAVITY Collaboration; Abuter, R.; Aimar, N.; Amorim, A.; Ball, J.; Bauböck, M.; Gillessen, S.; Widmann, F.; Heissel, G. (December 14, 2021). "Mass distribution in the Galactic Center based on interferometric astrometry of multiple stellar orbits" . Astronomy & Astrophysics . 657 : L12. arXiv : 2112.07478 . doi : 10.1051/0004-6361/202142465 . ISSN   0004-6361 . S2CID   245131377 . ^ Eckart, A.; Genzel, R.; Ott, T.; Schödel, R. (April 11, 2002). "Stellar orbits near Sagittarius A*" . Monthly Notices of the Royal Astronomical Society . 331 (4): 917– 934. arXiv : astro-ph/0201031 . Bibcode : 2002MNRAS.331..917E . doi : 10.1046/j.1365-8711.2002.05237.x . ISSN   0035-8711 . S2CID   11167996 . ^ Peissker, Florian; Eckart, Andreas; Parsa, Marzieh (January 2020). "S62 on a 9.9 year orbit around SgrA*" . The Astrophysical Journal . 889 (1): 61. arXiv : 2002.02341 . Bibcode : 2020ApJ...889...61P . doi : 10.3847/1538-4357/ab5afd . S2CID   211043784 . ^ GRAVITY Collaboration (2021). "Detection of faint stars near Sagittarius A* with GRAVITY" (PDF) . Astronomy & Astrophysics . 645 : A127. arXiv : 2011.03058 . Bibcode : 2021A&A...645A.127G . doi : 10.1051/0004-6361/202039544 . ISSN   0004-6361 . Retrieved December 29, 2024 . ^ Peißker, Florian; Eckart, Andreas; Zajaček, Michal; Basel, Ali; Parsa, Marzieh (August 2020). "S62 and S4711: Indications of a Population of Faint Fast-moving Stars inside the S2 Orbit—S4711 on a 7.6 yr Orbit around Sgr A*" . The Astrophysical Journal . 889 (50): 5. arXiv : 2008.04764 . Bibcode : 2020ApJ...899...50P . doi : 10.3847/1538-4357/ab9c1c . S2CID   221095771 . ^ NĂŠss, S. (October 4, 2019). "Galactic center S-star orbital parameters" . ^ Matson, John (October 22, 2012). "Gas Guzzler: Cloud Could Soon Meet Its Demise in Milky Way's Black Hole" . Scientific American. Archived from the original on June 19, 2013 . Retrieved October 30, 2012 . ^ a b Gillessen, S.; Genzel, R.; Fritz, T. K.; Quataert, E.; Alig, C.; Burkert, A.; Cuadra, J.; Eisenhauer, F.; Pfuhl, O.; Dodds-Eden, K.; Gammie, C. F.; Ott, T. (January 2012). "A gas cloud on its way towards the supermassive black hole at the Galactic Centre". Nature . 481 (7379): 51– 54. arXiv : 1112.3264 . Bibcode : 2012Natur.481...51G . doi : 10.1038/nature10652 . ISSN   0028-0836 . PMID   22170607 . S2CID   4410915 . ^ a b c Witzel, G.; Ghez, A. M.; Morris, M. R.; Sitarski, B. N.; Boehle, A.; Naoz, S.; Campbell, R.; Becklin, E. E.; G. Canalizo; Chappell, S.; Do, T.; Lu, J. R.; Matthews, K.; Meyer, L.; Stockton, A.; Wizinowich, P.; Yelda, S. (January 1, 2014). "Detection of Galactic Center Source G2 at 3.8 ÎŒm during Periapse Passage". Astrophysical Journal Letters . 796 (1): L8. arXiv : 1410.1884 . Bibcode : 2014ApJ...796L...8W . doi : 10.1088/2041-8205/796/1/L8 . S2CID   36797915 . ^ Bartos, Imre; Haiman, ZoltĂĄn; Kocsis, Bence; MĂĄrka, Szabolcs (May 2013). "Gas Cloud G2 Can Illuminate the Black Hole Population Near the Galactic Center". Physical Review Letters . 110 (22): 221102 (5 pages). arXiv : 1302.3220 . Bibcode : 2013PhRvL.110v1102B . doi : 10.1103/PhysRevLett.110.221102 . PMID   23767710 . S2CID   12284209 . ^ de la Fuente Marcos, R.; de la Fuente Marcos, C. (August 2013). "Colliding with G2 near the Galactic Centre: a geometrical approach" . Monthly Notices of the Royal Astronomical Society: Letters . 435 (1): L19– L23. arXiv : 1306.4921 . Bibcode : 2013MNRAS.435L..19D . doi : 10.1093/mnrasl/slt085 . S2CID   119287777 . ^ Morris, Mark (January 4, 2012). "Astrophysics: The Final Plunge" . Nature . 481 (7379): 32– 33. Bibcode : 2012Natur.481...32M . doi : 10.1038/nature10767 . PMID   22170611 . S2CID   664513 . ^ Gillessen. "Wiki Page of Proposed Observations of G2 Passage" . Archived from the original on February 1, 2014 . Retrieved October 30, 2012 . ^ "A Black Hole's Dinner is Fast Approaching" . ESO. December 14, 2011. Archived from the original on February 13, 2012 . Retrieved February 27, 2015 . ^ H Hirschfeld, Robert (October 22, 2012). "Milky Way's black hole getting ready for snack" . Lawrence Livermore National Laboratory . Archived from the original on June 19, 2013 . Retrieved February 27, 2015 . ^ Taylor Tillman, Nola (April 28, 2014). "Doomed Space Cloud Nears Milky Way's Black Hole as Scientists Watch" . Space.com . Retrieved September 15, 2024 . Cosmic encounter that might reveal new secrets on how such supermassive black holes evolve; We get to watch it unfolding in a human lifetime, which is very unusual and very exciting ^ a b Cowen, Ron (2014). "Why galactic black hole fireworks were a flop : Nature News & Comment" . Nature . doi : 10.1038/nature.2014.15591 . S2CID   124346286 . Archived from the original on February 19, 2015 . Retrieved February 27, 2015 . ^ Pfuhl, Oliver; Gillessen, Stefan; Eisenhauer, Frank; Genzel, Reinhard; Plewa, Philipp M.; Thomas Ott; Ballone, Alessandro; Schartmann, Marc; Burkert, Andreas (2015). "The Galactic Center Cloud G2 and its Gas Streamer". The Astrophysical Journal . 798 (2): 111. arXiv : 1407.4354 . Bibcode : 2015ApJ...798..111P . doi : 10.1088/0004-637x/798/2/111 . ISSN   0004-637X . S2CID   118440030 . ^ "How G2 survived the black hole at our Milky Way's heart - EarthSky.org" . November 4, 2014. Archived from the original on February 5, 2016 . Retrieved February 14, 2016 . ^ "Simulation of gas cloud after close approach to the black hole at the centre of the Milky Way" . ESO. Archived from the original on March 7, 2015 . Retrieved February 27, 2015 . Backer, D. C. & Sramek, R. A. (October 20, 1999). "Proper Motion of the Compact, Nonthermal Radio Source in the Galactic Center, Sagittarius A*". The Astrophysical Journal . 524 (2): 805– 815. arXiv : astro-ph/9906048 . Bibcode : 1999ApJ...524..805B . doi : 10.1086/307857 . ISSN   0004-637X . S2CID   18858138 . Gillessen, Stefan; et al. (February 23, 2009). "Monitoring stellar orbits around the Massive Black Hole in the Galactic Center". The Astrophysical Journal . 692 (2): 1075– 1109. arXiv : 0810.4674 . Bibcode : 2009ApJ...692.1075G . doi : 10.1088/0004-637X/692/2/1075 . S2CID   1431308 . Melia, Fulvio (2007). The galactic supermassive black hole . Princeton: Princeton Univ. ISBN   978-0-691-13129-0 . O'Neill, Ian (December 10, 2008). "Beyond Any Reasonable Doubt: A Supermassive Black Hole Lives in Centre of Our Galaxy" . Universe Today . Osterbrock, Donald E. & Ferland, Gary J. (2006). Astrophysics of gaseous nebulae and active galactic nuclei (2nd ed.). Mill Valley, California: University Science Books. ISBN   978-1-891389-34-4 . Reid, M. J.; Brunthaler, A. (December 2004). "The Proper Motion of Sagittarius A*. II. The Mass of Sagittarius A*". The Astrophysical Journal . 616 (2): 872– 884. arXiv : astro-ph/0408107 . Bibcode : 2004ApJ...616..872R . doi : 10.1086/424960 . ISSN   0004-637X . S2CID   16568545 . Schödel, R.; et al. (October 2002). "A star in a 15.2-year orbit around the supermassive black hole at the centre of the Milky Way". Nature . 419 (6908): 694– 696. arXiv : astro-ph/0210426 . Bibcode : 2002Natur.419..694S . doi : 10.1038/nature01121 . ISSN   0028-0836 . PMID   12384690 . S2CID   4302128 . Schödel, R.; Merritt, D. ; Eckart, A. (July 2009). "The nuclear star cluster of the Milky Way: proper motions and mass". Astronomy & Astrophysics . 502 (1): 91– 111. arXiv : 0902.3892 . Bibcode : 2009A&A...502...91S . doi : 10.1051/0004-6361/200810922 . ISSN   0004-6361 . S2CID   219559 . Melia, Fulvio (2003). The black hole at the center of our galaxy . Princeton: Princeton University Press. ISBN   978-0-691-09505-9 . Doeleman, Sheperd S.; et al. (September 2008). "Event-horizon-scale structure in the supermassive black hole candidate at the Galactic Centre". Nature . 455 (7209): 78– 80. arXiv : 0809.2442 . Bibcode : 2008Natur.455...78D . doi : 10.1038/nature07245 . ISSN   0028-0836 . PMID   18769434 . S2CID   4424735 . Eckart, Andreas; Schödel, Rainer; Straubmeier, Christian Michael; Straubmeier, Christian (2005). The black hole at the center of the Milky Way . London: Imperial College Press. ISBN   978-1-86094-567-0 . Eisenhauer, F.; Schdel, R.; Genzel, R.; Ott, T.; Tecza, M.; Abuter, R.; Eckart, A.; Alexander, T.; et al. (November 10, 2003). "A Geometric Determination of the Distance to the Galactic Center". The Astrophysical Journal . 597 (2): L121– L124. arXiv : astro-ph/0306220 . Bibcode : 2003ApJ...597L.121E . doi : 10.1086/380188 . ISSN   0004-637X . S2CID   16425333 . The Event Horizon Telescope Collaboration (April 10, 2019). "First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole" . The Astrophysical Journal Letters . 875 (1): L1. arXiv : 1906.11238 . Bibcode : 2019ApJ...875L...1E . doi : 10.3847/2041-8213/ab0ec7 . S2CID   145906806 . Ghez, A. M.; et al. (April 1, 2003). "The First Measurement of Spectral Lines in a Short-Period Star Bound to the Galaxy's Central Black Hole: A Paradox of Youth". The Astrophysical Journal . 586 (2): L127– L131. arXiv : astro-ph/0302299 . Bibcode : 2003ApJ...586L.127G . doi : 10.1086/374804 . S2CID   11388341 . Ghez, A. M.; et al. (December 20, 2008). "Measuring Distance and Properties of the Milky Way's Central Supermassive Black Hole with Stellar Orbits". The Astrophysical Journal . 689 (2): 1044– 1062. arXiv : 0808.2870 . Bibcode : 2008ApJ...689.1044G . doi : 10.1086/592738 . ISSN   0004-637X . S2CID   18335611 . Reynolds, Christopher S. (September 2008). "Bringing black holes into focus". Nature . 455 (7209): 39– 40. Bibcode : 2008Natur.455...39R . doi : 10.1038/455039a . ISSN   0028-0836 . PMID   18769426 . S2CID   205040663 . Wheeler, J. Craig (2007). Cosmic catastrophes: exploding stars, black holes, and mapping the universe (2nd ed.). Cambridge; New York: Cambridge University Press . ISBN   978-0-521-85714-7 . OCLC   73954922 . Peißker, F.; Zajaček, M.; Melamed, M.; Ali, B.; Singhal, M.; Dassel, T.; Eckart, A.; Karas, V. (June 2024). "Candidate young stellar objects in the S-cluster: Kinematic analysis of a subpopulation of the low-mass G objects close to Sgr A*". Astronomy & Astrophysics . 686 : A235. arXiv : 2406.09916 . Bibcode : 2024A&A...686A.235P . doi : 10.1051/0004-6361/202449729 . ISSN   0004-6361 . Rayne, Elizabeth (July 4, 2024). "Swarm of dusty young stars found around our galaxy's central black hole" . Ars Technica . Retrieved July 5, 2024 . Is there a Supermassive Black Hole at the Center of the Milky Way? ( arXiv preprint) 2004 paper deducing mass of central black hole from orbits of 7 stars ( arXiv preprint) ESO video clip of orbiting star (533 KB MPEG Video) The Proper Motion of Sgr A* and the Mass of Sgr A* (PDF) NRAO article regarding VLBI radio imaging of Sgr A* Peering into a Black Hole , 2015 New York Times video Image of supermassive black hole Sagittarius A* (2022) , Harvard Center for Astrophysics Video (65:30) – EHT conference presenting first image of Sgr A* on YouTube ( NSF ; 12 May 2022)
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[Jump to content](https://en.wikipedia.org/wiki/Sagittarius_A*#bodyContent) Main menu Main menu move to sidebar hide Navigation - [Main page](https://en.wikipedia.org/wiki/Main_Page "Visit the main page [z]") - [Contents](https://en.wikipedia.org/wiki/Wikipedia:Contents "Guides to browsing Wikipedia") - [Current events](https://en.wikipedia.org/wiki/Portal:Current_events "Articles related to current events") - [Random article](https://en.wikipedia.org/wiki/Special:Random "Visit a randomly selected article [x]") - [About Wikipedia](https://en.wikipedia.org/wiki/Wikipedia:About "Learn about Wikipedia and how it works") - [Contact us](https://en.wikipedia.org/wiki/Wikipedia:Contact_us "How to contact Wikipedia") Contribute - [Help](https://en.wikipedia.org/wiki/Help:Contents "Guidance on how to use and edit Wikipedia") - [Learn to edit](https://en.wikipedia.org/wiki/Help:Introduction "Learn how to edit Wikipedia") - [Community portal](https://en.wikipedia.org/wiki/Wikipedia:Community_portal "The hub for editors") - [Recent changes](https://en.wikipedia.org/wiki/Special:RecentChanges "A list of recent changes to Wikipedia [r]") - [Upload file](https://en.wikipedia.org/wiki/Wikipedia:File_upload_wizard "Add images or other media for use on Wikipedia") - [Special pages](https://en.wikipedia.org/wiki/Special:SpecialPages "A list of all special pages [q]") [![](https://en.wikipedia.org/static/images/icons/enwiki-25.svg) ![Wikipedia](https://en.wikipedia.org/static/images/mobile/copyright/wikipedia-wordmark-en-25.svg) ![The Free Encyclopedia](https://en.wikipedia.org/static/images/mobile/copyright/wikipedia-tagline-en-25.svg)](https://en.wikipedia.org/wiki/Main_Page) [Search](https://en.wikipedia.org/wiki/Special:Search "Search Wikipedia [f]") Appearance - [Donate](https://donate.wikimedia.org/?wmf_source=donate&wmf_medium=sidebar&wmf_campaign=en.wikipedia.org&uselang=en) - [Create account](https://en.wikipedia.org/w/index.php?title=Special:CreateAccount&returnto=Sagittarius+A%2A "You are encouraged to create an account and log in; however, it is not mandatory") - [Log in](https://en.wikipedia.org/w/index.php?title=Special:UserLogin&returnto=Sagittarius+A%2A "You're encouraged to log in; however, it's not mandatory. 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[o]") ## Contents move to sidebar hide - [(Top)](https://en.wikipedia.org/wiki/Sagittarius_A*) - [1 Observation and description](https://en.wikipedia.org/wiki/Sagittarius_A*#Observation_and_description) - [2 History](https://en.wikipedia.org/wiki/Sagittarius_A*#History) - [3 Central black hole](https://en.wikipedia.org/wiki/Sagittarius_A*#Central_black_hole) - [4 Orbiting stars](https://en.wikipedia.org/wiki/Sagittarius_A*#Orbiting_stars) - [5 Discovery of G2 gas cloud on an accretion course](https://en.wikipedia.org/wiki/Sagittarius_A*#Discovery_of_G2_gas_cloud_on_an_accretion_course) - [6 See also](https://en.wikipedia.org/wiki/Sagittarius_A*#See_also) - [7 Notes](https://en.wikipedia.org/wiki/Sagittarius_A*#Notes) - [8 References](https://en.wikipedia.org/wiki/Sagittarius_A*#References) - [9 Further reading](https://en.wikipedia.org/wiki/Sagittarius_A*#Further_reading) - [10 External links](https://en.wikipedia.org/wiki/Sagittarius_A*#External_links) Toggle the table of contents # Sagittarius A\* 57 languages - [Afrikaans](https://af.wikipedia.org/wiki/Sagittarius_A* "Sagittarius A* – Afrikaans") - [Ű§Ù„ŰčŰ±ŰšÙŠŰ©](https://ar.wikipedia.org/wiki/%D8%A7%D9%84%D8%B1%D8%A7%D9%85%D9%8A_A* "Ű§Ù„Ű±Ű§Ù…ÙŠ A* – Arabic") - [Ű§Ù„ŰŻŰ§Ű±ŰŹŰ©](https://ary.wikipedia.org/wiki/%D8%B3%D8%A7%D8%AC%D9%8A%D8%B7%D8%A7%D8%B1%D9%8A%D9%88%D8%B3_A_%D9%86%D8%AC%D9%85%D8%A9 "ŰłŰ§ŰŹÙŠŰ·Ű§Ű±ÙŠÙˆŰł A Ù†ŰŹÙ…Ű© – Moroccan Arabic") - [БългарсĐșĐž](https://bg.wikipedia.org/wiki/%D0%A1%D1%82%D1%80%D0%B5%D0%BB%D0%B5%D1%86_%D0%90* "ХтрДлДц А* – Bulgarian") - [àŠŹàŠŸàŠ‚àŠČàŠŸ](https://bn.wikipedia.org/wiki/%E0%A6%A7%E0%A6%A8%E0%A7%81_%E0%A6%8F* "àŠ§àŠšà§ àŠ* – Bangla") - [CatalĂ ](https://ca.wikipedia.org/wiki/Sagitari_A* "Sagitari A* – Catalan") - [ČeĆĄtina](https://cs.wikipedia.org/wiki/Sagittarius_A* "Sagittarius A* – Czech") - [Dansk](https://da.wikipedia.org/wiki/Sagittarius_A* "Sagittarius A* – Danish") - [Deutsch](https://de.wikipedia.org/wiki/Sagittarius_A* "Sagittarius A* – German") - [ΕλληΜÎčÎșÎŹ](https://el.wikipedia.org/wiki/%CE%A4%CE%BF%CE%BE%CF%8C%CF%84%CE%B7%CF%82_A* "Î€ÎżÎŸÏŒÏ„Î·Ï‚ A* – Greek") - [Esperanto](https://eo.wikipedia.org/wiki/Sagittarius_A* "Sagittarius A* – Esperanto") - [Español](https://es.wikipedia.org/wiki/Sagitario_A* "Sagitario A* – Spanish") - [Eesti](https://et.wikipedia.org/wiki/Sagittarius_A* "Sagittarius A* – Estonian") - [Euskara](https://eu.wikipedia.org/wiki/Sagittarius_A* "Sagittarius A* – Basque") - [ÙŰ§Ű±ŰłÛŒ](https://fa.wikipedia.org/wiki/%DA%A9%D9%85%D8%A7%D9%86_%D8%A7%DB%8C* "Ú©Ù…Ű§Ù† Ű§ÛŒ* – Persian") - [Suomi](https://fi.wikipedia.org/wiki/Sagittarius_A* "Sagittarius A* – Finnish") - [Français](https://fr.wikipedia.org/wiki/Sagittarius_A* "Sagittarius A* – French") - [Gaeilge](https://ga.wikipedia.org/wiki/Sagittarius_A* "Sagittarius A* – Irish") - [ŚąŚ‘ŚšŚ™ŚȘ](https://he.wikipedia.org/wiki/%D7%A7%D7%A9%D7%AA_A* "Ś§Ś©ŚȘ A* – Hebrew") - [à€čà€żà€šà„à€Šà„€](https://hi.wikipedia.org/wiki/%E0%A4%A7%E0%A4%A8%E0%A5%81_%E0%A4%8F* "à€§à€šà„ à€* – Hindi") - [Magyar](https://hu.wikipedia.org/wiki/Sagittarius_A* "Sagittarius A* – Hungarian") - [Interlingua](https://ia.wikipedia.org/wiki/Sagittario_A* "Sagittario A* – Interlingua") - [Bahasa Indonesia](https://id.wikipedia.org/wiki/Sagittarius_A* "Sagittarius A* – Indonesian") - [Italiano](https://it.wikipedia.org/wiki/Sagittarius_A* "Sagittarius A* – Italian") - [æ—„æœŹèȘž](https://ja.wikipedia.org/wiki/%E3%81%84%E3%81%A6%E5%BA%A7A* "いどćș§A* – Japanese") - [áƒ„áƒáƒ áƒ—áƒŁáƒšáƒ˜](https://ka.wikipedia.org/wiki/%E1%83%9B%E1%83%A8%E1%83%95%E1%83%98%E1%83%9A%E1%83%93%E1%83%9D%E1%83%A1%E1%83%90%E1%83%9C%E1%83%98_A* "მჹვილდოსანი A* – Georgian") - [한ꔭ얎](https://ko.wikipedia.org/wiki/%EA%B6%81%EC%88%98%EC%9E%90%EB%A6%AC_A* "ê¶ìˆ˜ìžëŠŹ A* – Korean") - [Ripoarisch](https://ksh.wikipedia.org/wiki/Sajittarius_A* "Sajittarius A* – Colognian") - [Latina](https://la.wikipedia.org/wiki/Sagittarius_A* "Sagittarius A* – Latin") - [LĂ«tzebuergesch](https://lb.wikipedia.org/wiki/Sagittarius_A* "Sagittarius A* – Luxembourgish") - [Limburgs](https://li.wikipedia.org/wiki/Sagittarius_A* "Sagittarius A* – Limburgish") - [LietuviĆł](https://lt.wikipedia.org/wiki/%C5%A0aulio_A* "Ć aulio A* – Lithuanian") - [МаĐșĐ”ĐŽĐŸĐœŃĐșĐž](https://mk.wikipedia.org/wiki/%D0%A1%D1%82%D1%80%D0%B5%D0%BB%D0%B5%D1%86_%D0%90* "ХтрДлДц А* – Macedonian") - [Bahasa Melayu](https://ms.wikipedia.org/wiki/Sagittarius_A* "Sagittarius A* – Malay") - [Nederlands](https://nl.wikipedia.org/wiki/Sagittarius_A* "Sagittarius A* – Dutch") - [Norsk nynorsk](https://nn.wikipedia.org/wiki/Sagittarius_A* "Sagittarius A* – Norwegian Nynorsk") - [Norsk bokmĂ„l](https://no.wikipedia.org/wiki/Sagittarius_A* "Sagittarius A* – Norwegian BokmĂ„l") - [Polski](https://pl.wikipedia.org/wiki/Sagittarius_A* "Sagittarius A* – Polish") - [PortuguĂȘs](https://pt.wikipedia.org/wiki/Sagittarius_A* "Sagittarius A* – Portuguese") - [RomĂąnă](https://ro.wikipedia.org/wiki/Sagittarius_A* "Sagittarius A* – Romanian") - [РуссĐșĐžĐč](https://ru.wikipedia.org/wiki/%D0%A1%D1%82%D1%80%D0%B5%D0%BB%D0%B5%D1%86_A* "ХтрДлДц A* – Russian") - [Саха тыла](https://sah.wikipedia.org/wiki/%D0%9E%D1%85%D1%87%D1%83%D1%82_A* "Охчут A* – Yakut") - [Simple English](https://simple.wikipedia.org/wiki/Sagittarius_A* "Sagittarius A* – Simple English") - [Slovenčina](https://sk.wikipedia.org/wiki/Sagittarius_A* "Sagittarius A* – Slovak") - [Slovenơčina](https://sl.wikipedia.org/wiki/Strelec_A* "Strelec A* – Slovenian") - [СрпсĐșĐž / srpski](https://sr.wikipedia.org/wiki/Strelac_A* "Strelac A* – Serbian") - [Svenska](https://sv.wikipedia.org/wiki/Sagittarius_A* "Sagittarius A* – Swedish") - [Kiswahili](https://sw.wikipedia.org/wiki/Sagittarius_A* "Sagittarius A* – Swahili") - [àź€àźźàźżàźŽàŻ](https://ta.wikipedia.org/wiki/%E0%AE%A4%E0%AE%A9%E0%AF%81%E0%AE%9A%E0%AF%81_%E0%AE%8F* "àź€àź©àŻàźšàŻ àź* – Tamil") - [àč„àž—àžą](https://th.wikipedia.org/wiki/%E0%B8%84%E0%B8%99%E0%B8%A2%E0%B8%B4%E0%B8%87%E0%B8%98%E0%B8%99%E0%B8%B9%E0%B9%80%E0%B8%AD* "àž„àž™àžąàžŽàž‡àž˜àž™àžčàč€àž­* – Thai") - [TĂŒrkçe](https://tr.wikipedia.org/wiki/Sagittarius_A* "Sagittarius A* – Turkish") - [ĐŁĐșŃ€Đ°Ń—ĐœŃŃŒĐșĐ°](https://uk.wikipedia.org/wiki/%D0%A1%D1%82%D1%80%D1%96%D0%BB%D0%B5%D1%86%D1%8C_A* "ĐĄŃ‚Ń€Ń–Đ»Đ”Ń†ŃŒ A* – Ukrainian") - [Tiáșżng Việt](https://vi.wikipedia.org/wiki/Nh%C3%A2n_M%C3%A3_A* "NhĂąn MĂŁ A* – Vietnamese") - [Winaray](https://war.wikipedia.org/wiki/Sagittarius_A* "Sagittarius A* – Waray") - [ćŽèŻ­](https://wuu.wikipedia.org/wiki/%E4%BA%BA%E9%A9%AC%E5%BA%A7A* "äșșé©Źćș§A* – Wu") - [çČ”èȘž](https://zh-yue.wikipedia.org/wiki/%E4%BA%BA%E9%A6%AC%E5%BA%A7A* "äșș銏ćș§A* – Cantonese") - [äž­æ–‡](https://zh.wikipedia.org/wiki/%E4%BA%BA%E9%A6%AC%E5%BA%A7A* "äșș銏ćș§A* – Chinese") [Edit links](https://www.wikidata.org/wiki/Special:EntityPage/Q237284#sitelinks-wikipedia "Edit interlanguage links") - [Article](https://en.wikipedia.org/wiki/Sagittarius_A* "View the content page [c]") - [Talk](https://en.wikipedia.org/wiki/Talk:Sagittarius_A* "Discuss improvements to the content page [t]") English - [Read](https://en.wikipedia.org/wiki/Sagittarius_A*) - [Edit](https://en.wikipedia.org/w/index.php?title=Sagittarius_A*&action=edit "Edit this page [e]") - [View history](https://en.wikipedia.org/w/index.php?title=Sagittarius_A*&action=history "Past revisions of this page [h]") Tools Tools move to sidebar hide Actions - 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[Get shortened URL](https://en.wikipedia.org/w/index.php?title=Special:UrlShortener&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FSagittarius_A%2A) Print/export - [Download as PDF](https://en.wikipedia.org/w/index.php?title=Special:DownloadAsPdf&page=Sagittarius_A%2A&action=show-download-screen "Download this page as a PDF file") - [Printable version](https://en.wikipedia.org/w/index.php?title=Sagittarius_A*&printable=yes "Printable version of this page [p]") In other projects - [Wikimedia Commons](https://commons.wikimedia.org/wiki/Category:Sagittarius_A*) - [Wikidata item](https://www.wikidata.org/wiki/Special:EntityPage/Q237284 "Structured data on this page hosted by Wikidata [g]") Appearance move to sidebar hide [Coordinates](https://en.wikipedia.org/wiki/Celestial_coordinate_system "Celestial coordinate system"): [![Sky map](https://upload.wikimedia.org/wikipedia/commons/thumb/e/e4/Jupiter_and_moon.png/20px-Jupiter_and_moon.png)](https://en.wikipedia.org/wiki/File:Jupiter_and_moon.png "Sky map") [17h 45m 40.0409s, −29° 0â€Č 28.118″](http://www.wikisky.org/?ra=17.761122472222&de=-29.007810555556&zoom=7&show_grid=1&show_constellation_lines=1&show_constellation_boundaries=1&show_const_names=1&show_galaxies=1&img_source=IMG_all) From Wikipedia, the free encyclopedia Supermassive black hole at the center of the Milky Way This article is about the black hole. For the surrounding region, see [Sagittarius A](https://en.wikipedia.org/wiki/Sagittarius_A "Sagittarius A"). | | | |---|---| | [![](https://upload.wikimedia.org/wikipedia/commons/thumb/9/96/EHT_Saggitarius_A_black_hole.tif/lossy-page1-250px-EHT_Saggitarius_A_black_hole.tif.jpg)](https://en.wikipedia.org/wiki/File:EHT_Saggitarius_A_black_hole.tif) Sagittarius A\* imaged by the [Event Horizon Telescope](https://en.wikipedia.org/wiki/Event_Horizon_Telescope "Event Horizon Telescope") in 2017, released in 2022 | | | Observation data [Epoch](https://en.wikipedia.org/wiki/Epoch_\(astronomy\) "Epoch (astronomy)") [J2000](https://en.wikipedia.org/wiki/J2000 "J2000") [Equinox](https://en.wikipedia.org/wiki/Equinox_\(celestial_coordinates\) "Equinox (celestial coordinates)") [J2000](https://en.wikipedia.org/wiki/J2000 "J2000") | | | [Constellation](https://en.wikipedia.org/wiki/Constellation "Constellation") | [Sagittarius](https://en.wikipedia.org/wiki/Sagittarius_\(constellation\) "Sagittarius (constellation)") | | [Right ascension](https://en.wikipedia.org/wiki/Right_ascension "Right ascension") | 17h 45m 40.0409s | | [Declination](https://en.wikipedia.org/wiki/Declination "Declination") | −29° 0â€Č 28.118″[\[1\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-1) | | Details | | | **[Mass](https://en.wikipedia.org/wiki/Stellar_mass "Stellar mass")** | 8\.54×1036 kg 4\.297×106[\[2\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-GRAVITY-2) [M☉](https://en.wikipedia.org/wiki/Solar_mass "Solar mass") | | [Astrometry](https://en.wikipedia.org/wiki/Astrometry "Astrometry") | | | **[Distance](https://en.wikipedia.org/wiki/Distance_\(astronomy\) "Distance (astronomy)")** | 26996±33[\[2\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-GRAVITY-2) [ly](https://en.wikipedia.org/wiki/Light-year "Light-year") (8277±9[\[2\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-GRAVITY-2) [pc](https://en.wikipedia.org/wiki/Parsec "Parsec")) | | Database references | | | **[SIMBAD](https://en.wikipedia.org/wiki/SIMBAD "SIMBAD")** | [data](https://simbad.cds.unistra.fr/simbad/sim-id?Ident=NAME+Sgr+A*) | **Sagittarius A\***, [abbreviated](https://en.wikipedia.org/wiki/Abbreviation "Abbreviation") as **Sgr A\*** ([/ˈsĂŠdʒ ˈeÉȘ stɑːr/](https://en.wikipedia.org/wiki/Help:IPA/English "Help:IPA/English") [*SADGE\-AY\-star*](https://en.wikipedia.org/wiki/Help:Pronunciation_respelling_key "Help:Pronunciation respelling key")[\[3\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-3)), is the [supermassive black hole](https://en.wikipedia.org/wiki/Supermassive_black_hole "Supermassive black hole")[\[4\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-4)[\[5\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-5)[\[6\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-plait-6) at the [Galactic Center](https://en.wikipedia.org/wiki/Galactic_Center "Galactic Center") of the [Milky Way](https://en.wikipedia.org/wiki/Milky_Way "Milky Way"). Viewed from Earth, it is located near the border of the constellations [Sagittarius](https://en.wikipedia.org/wiki/Sagittarius_\(constellation\) "Sagittarius (constellation)") and [Scorpius](https://en.wikipedia.org/wiki/Scorpius "Scorpius"), about 5.6° south of the [ecliptic](https://en.wikipedia.org/wiki/Ecliptic "Ecliptic"),[\[7\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-7) visually close to the [Butterfly Cluster](https://en.wikipedia.org/wiki/Butterfly_Cluster "Butterfly Cluster") (M6) and [Lambda Scorpii](https://en.wikipedia.org/wiki/Lambda_Scorpii "Lambda Scorpii"). Sagittarius A\* is a bright and very compact [astronomical radio source](https://en.wikipedia.org/wiki/Astronomical_radio_source "Astronomical radio source"). In May 2022, astronomers released the first image of the [accretion disk](https://en.wikipedia.org/wiki/Accretion_disk "Accretion disk") around the event horizon of Sagittarius A\*,[\[8\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-8) using the [Event Horizon Telescope](https://en.wikipedia.org/wiki/Event_Horizon_Telescope "Event Horizon Telescope"), a world-wide network of radio observatories.[\[9\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-AJ-202205-9) This is the second confirmed image of a black hole, after [Messier 87's supermassive black hole](https://en.wikipedia.org/wiki/Messier_87#Supermassive_black_hole_M87* "Messier 87") in 2019.[\[10\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-ESO2208-10)[\[11\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-NYT-20220512-11) The black hole itself is not seen; as light is incapable of escaping the immense gravitational force of a black hole, only nearby objects whose behavior is influenced by the black hole can be observed. The observed radio and infrared energy emanates from gas and dust heated to millions of degrees while falling into the black hole.[\[12\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-DetectionOfBlackHoleSrgA-12) Sgr A\* was discovered in 1974 by [Bruce Balick](https://en.wikipedia.org/wiki/Bruce_Balick "Bruce Balick") and Robert L. Brown,[\[13\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Intense_sub-arcsecond_structure_in-13)[\[14\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Melia_2007,_p._7-14) and the [asterisk](https://en.wikipedia.org/wiki/Asterisk "Asterisk") **\*** was assigned in 1982 by Brown,[\[15\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-15) who understood that the strongest radio emission from the center of the galaxy appeared to be due to a compact non-thermal radio object embedded in a larger, and much brighter, radio source, [Sagittarius A](https://en.wikipedia.org/wiki/Sagittarius_A "Sagittarius A") (Sgr A). The observation of several stars orbiting Sagittarius A\*, particularly [star S2](https://en.wikipedia.org/wiki/S2_\(star\) "S2 (star)"), have been used to determine the mass and upper limits on the radius of the object. Based on the mass and the precise radius limits obtained, astronomers concluded that Sagittarius A\* was the central supermassive black hole of the Milky Way galaxy.[\[16\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Henderson-16) The current best estimate of its mass is 4.297±0\.012 million [solar masses](https://en.wikipedia.org/wiki/Solar_mass "Solar mass").[\[2\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-GRAVITY-2) [Reinhard Genzel](https://en.wikipedia.org/wiki/Reinhard_Genzel "Reinhard Genzel") and [Andrea Ghez](https://en.wikipedia.org/wiki/Andrea_M._Ghez "Andrea M. Ghez") were each awarded a quarter share in the 2020 [Nobel Prize in Physics](https://en.wikipedia.org/wiki/Nobel_Prize_in_Physics "Nobel Prize in Physics") for their discovery that Sagittarius A\* is a supermassive compact object, for which a [black hole](https://en.wikipedia.org/wiki/Black_hole "Black hole") was the only explanation. [Sir Roger Penrose](https://en.wikipedia.org/wiki/Roger_Penrose "Roger Penrose") received the other half "for the discovery that black hole formation is a robust prediction of the [general theory of relativity](https://en.wikipedia.org/wiki/General_theory_of_relativity "General theory of relativity")".[\[17\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-17) ## Observation and description \[[edit](https://en.wikipedia.org/w/index.php?title=Sagittarius_A*&action=edit&section=1 "Edit section: Observation and description")\] [![](https://upload.wikimedia.org/wikipedia/commons/thumb/e/e8/Sagittarius_Astar_in_the_constellation_of_Sagittarius.tif/lossy-page1-250px-Sagittarius_Astar_in_the_constellation_of_Sagittarius.tif.jpg)](https://en.wikipedia.org/wiki/File:Sagittarius_Astar_in_the_constellation_of_Sagittarius.tif) Sagittarius A\* in the constellation of Sagittarius. The black hole is marked with a red circle within the constellation of Sagittarius (The Archer). This map shows most of the stars visible to the unaided eye under good conditions. [![](https://upload.wikimedia.org/wikipedia/commons/thumb/e/e1/Eso2208-eht-mwe.tif/lossy-page1-250px-Eso2208-eht-mwe.tif.jpg)](https://en.wikipedia.org/wiki/File:Eso2208-eht-mwe.tif) Size comparison between Sagittarius A\* and [M87\*](https://en.wikipedia.org/wiki/Messier_87#Supermassive_black_hole_M87* "Messier 87"). The diameter of Sagittarius A\* is smaller than the orbit of [Mercury](https://en.wikipedia.org/wiki/Mercury_\(planet\) "Mercury (planet)"). On May 12, 2022, the first image of Sagittarius A\* was released by the [Event Horizon Telescope Collaboration](https://en.wikipedia.org/wiki/Event_Horizon_Telescope_Collaboration "Event Horizon Telescope Collaboration"). The image, which is based on radio interferometer data taken in 2017, confirms that the object contains a black hole. This is the second image of a black hole,[\[10\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-ESO2208-10)[\[18\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Shadow-18) and took five years of calculations to process.[\[19\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-19) The data were collected by eight radio observatories at six geographical sites. Radio images are produced from data by [aperture synthesis](https://en.wikipedia.org/wiki/Aperture_synthesis "Aperture synthesis"), usually from night-long observations of stable sources. The radio emission from Sgr A\* varies on the order of minutes, complicating the analysis.[\[20\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-20) Their result gives an overall [angular size](https://en.wikipedia.org/wiki/Angular_diameter "Angular diameter") for the source of 51\.8±2\.3 [ÎŒas](https://en.wikipedia.org/wiki/Microarcsecond "Microarcsecond").[\[18\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Shadow-18) At a distance of 26,000 [light-years](https://en.wikipedia.org/wiki/Light-year "Light-year") (8,000 [parsecs](https://en.wikipedia.org/wiki/Parsec "Parsec")), this yields a diameter of 51.8 million kilometres (32.2 million miles).[\[a\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-dc1-21) For comparison, Earth is 150 million [kilometres](https://en.wikipedia.org/wiki/Kilometre "Kilometre") (1.0 [astronomical unit](https://en.wikipedia.org/wiki/Astronomical_unit "Astronomical unit"); 93 million [miles](https://en.wikipedia.org/wiki/Mile "Mile")) from the [Sun](https://en.wikipedia.org/wiki/Sun "Sun"), and [Mercury](https://en.wikipedia.org/wiki/Mercury_\(planet\) "Mercury (planet)") is 46 million km (0.31 AU; 29 million mi) from the Sun at [perihelion](https://en.wikipedia.org/wiki/Apsis "Apsis"). The [proper motion](https://en.wikipedia.org/wiki/Proper_motion "Proper motion") of Sgr A\* is approximately −2.70 [mas](https://en.wikipedia.org/wiki/Minute_and_second_of_arc "Minute and second of arc") per year for the [right ascension](https://en.wikipedia.org/wiki/Right_ascension "Right ascension") and −5.6 mas per year for the [declination](https://en.wikipedia.org/wiki/Declination "Declination").[\[21\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-22)[\[22\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-23)[\[23\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-24) The telescope's measurement of these black holes tested Einstein's [theory of relativity](https://en.wikipedia.org/wiki/Theory_of_relativity "Theory of relativity") more rigorously than has previously been done, and the results match perfectly.[\[11\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-NYT-20220512-11) In 2019, measurements made with the High-resolution Airborne Wideband Camera-Plus (HAWC+) mounted in the [SOFIA](https://en.wikipedia.org/wiki/Stratospheric_Observatory_for_Infrared_Astronomy "Stratospheric Observatory for Infrared Astronomy") aircraft[\[24\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-25) revealed that magnetic fields cause the surrounding ring of gas and dust, temperatures of which range from −280 to 17,500 °F (99.8 to 9,977.6 K; −173.3 to 9,704.4 °C),[\[25\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-26) to flow into an orbit around Sagittarius A\*, keeping black hole emissions low.[\[26\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-27) Astronomers have been unable to observe Sgr A\* in the [Visible spectrum](https://en.wikipedia.org/wiki/Visible_spectrum "Visible spectrum") because of the effect of 25 [magnitudes](https://en.wikipedia.org/wiki/Magnitude_\(astronomy\) "Magnitude (astronomy)") of [extinction](https://en.wikipedia.org/wiki/Extinction_\(astronomy\) "Extinction (astronomy)") (absorption and scattering) by dust and gas between the source and Earth.[\[27\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Osterbrock-28) ## History \[[edit](https://en.wikipedia.org/w/index.php?title=Sagittarius_A*&action=edit&section=2 "Edit section: History")\] In April 1933, [Karl Jansky](https://en.wikipedia.org/wiki/Karl_Guthe_Jansky "Karl Guthe Jansky"), considered one of the fathers of radio astronomy, discovered that a radio signal was coming from a location in the direction of the constellation of Sagittarius, towards the center of the Milky Way.[\[28\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-29) The radio source later became known as [Sagittarius A](https://en.wikipedia.org/wiki/Sagittarius_A "Sagittarius A"). His observations did not extend quite as far south as we now know to be the Galactic Center.[\[29\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-goss_history-30) Observations by [Jack Piddington](https://en.wikipedia.org/wiki/Jack_Piddington "Jack Piddington") and [Harry Minnett](https://en.wikipedia.org/wiki/Harry_Clive_Minnett "Harry Clive Minnett") using the [CSIRO](https://en.wikipedia.org/wiki/CSIRO "CSIRO") radio telescope at [Potts Hill Reservoir](https://en.wikipedia.org/wiki/Potts_Hill_Reservoirs_1_and_2 "Potts Hill Reservoirs 1 and 2"), in [Sydney](https://en.wikipedia.org/wiki/Sydney "Sydney") discovered a discrete and bright "Sagittarius-Scorpius" radio source,[\[30\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-piddington-31) which after further observation with the 80-foot (24-metre) CSIRO radio telescope at [Dover Heights](https://en.wikipedia.org/wiki/Dover_Heights "Dover Heights") was identified in a letter to *[Nature](https://en.wikipedia.org/wiki/Nature_\(journal\) "Nature (journal)")* as the probable Galactic Center.[\[31\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-galactic_centre_mcgee-32) Later observations showed that Sagittarius A actually consists of several overlapping sub-components; a bright and very compact component, Sgr A\*, was discovered on February 13 and 15, 1974, by Balick and Robert L. Brown using the baseline interferometer of the [National Radio Astronomy Observatory](https://en.wikipedia.org/wiki/National_Radio_Astronomy_Observatory "National Radio Astronomy Observatory").[\[13\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Intense_sub-arcsecond_structure_in-13)[\[14\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Melia_2007,_p._7-14) The name Sgr A\* was coined by Brown in a 1982 paper because the radio source was "exciting", and [excited states](https://en.wikipedia.org/wiki/Excited_state "Excited state") of atoms are denoted with asterisks.[\[32\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-33)[\[33\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-34) Since the 1980s, it has been evident that the central component of Sgr A\* is likely a black hole. In 1994, infrared and sub-millimetre spectroscopy studies by a [Berkeley](https://en.wikipedia.org/wiki/University_of_California,_Berkeley "University of California, Berkeley") team involving [Nobel Laureate](https://en.wikipedia.org/wiki/Nobel_Prize_in_Physics "Nobel Prize in Physics") [Charles H. Townes](https://en.wikipedia.org/wiki/Charles_H._Townes "Charles H. Townes") and future Nobel Prize Winner [Reinhard Genzel](https://en.wikipedia.org/wiki/Reinhard_Genzel "Reinhard Genzel") showed that the mass of Sgr A\* was tightly concentrated and on the order of 3 million Suns.[\[34\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-35) On October 16, 2002, an international team led by [Reinhard Genzel](https://en.wikipedia.org/wiki/Reinhard_Genzel "Reinhard Genzel") at the [Max Planck Institute for Extraterrestrial Physics](https://en.wikipedia.org/wiki/Max_Planck_Institute_for_Extraterrestrial_Physics "Max Planck Institute for Extraterrestrial Physics") reported the observation of the motion of the star [S2](https://en.wikipedia.org/wiki/S2_\(star\) "S2 (star)") near Sagittarius A\* throughout a period of ten years. According to the team's analysis, the data ruled out the possibility that Sgr A\* contains a cluster of dark stellar objects or a mass of [degenerate fermions](https://en.wikipedia.org/wiki/Degenerate_matter "Degenerate matter"), strengthening the evidence for a massive black hole. The observations of S2 used [near-infrared](https://en.wikipedia.org/wiki/Near-infrared "Near-infrared") (NIR) [interferometry](https://en.wikipedia.org/wiki/Astronomical_interferometer "Astronomical interferometer") (in the Ks-band, i.e. 2.1 [ÎŒm](https://en.wikipedia.org/wiki/%CE%9Cm "Μm")) because of reduced [interstellar extinction](https://en.wikipedia.org/wiki/Extinction_\(astronomy\) "Extinction (astronomy)") in this band. SiO [masers](https://en.wikipedia.org/wiki/Astrophysical_maser "Astrophysical maser") were used to align NIR images with radio observations, as they can be observed in both NIR and radio bands. The rapid motion of S2 (and other nearby stars) easily stood out against slower-moving stars along the line-of-sight so these could be subtracted from the images.[\[35\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-36)[\[36\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-37) [![](https://upload.wikimedia.org/wikipedia/commons/thumb/6/6d/Dusty_cloud_G2_passes_the_supermassive_black_hole_at_the_centre_of_the_Milky_Way.jpg/330px-Dusty_cloud_G2_passes_the_supermassive_black_hole_at_the_centre_of_the_Milky_Way.jpg)](https://en.wikipedia.org/wiki/File:Dusty_cloud_G2_passes_the_supermassive_black_hole_at_the_centre_of_the_Milky_Way.jpg) Dusty cloud G2 passes the supermassive black hole at the center of the Milky Way.[\[37\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-38) Composition of images taken at different times to show motion; colored blue when approaching the viewer, red when receding; time is left to right. Red cross marks the black hole. The VLBI radio observations of Sagittarius A\* could also be aligned centrally with the NIR images, so the focus of S2's elliptical orbit was found to coincide with the position of Sagittarius A\*. From examining the [Keplerian orbit](https://en.wikipedia.org/wiki/Kepler_orbit "Kepler orbit") of S2, they determined the mass of Sagittarius A\* to be 4\.1±0\.6 million [solar masses](https://en.wikipedia.org/wiki/Solar_mass "Solar mass"), confined in a volume with a radius no more than 17 light-hours (120 [AU](https://en.wikipedia.org/wiki/Astronomical_unit "Astronomical unit") \[18 [billion](https://en.wikipedia.org/wiki/1000000000_\(number\) "1000000000 (number)") [km](https://en.wikipedia.org/wiki/Kilometre "Kilometre"); 11 billion [mi](https://en.wikipedia.org/wiki/Mile "Mile")\]).[\[38\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-39) Later observations of the star S14 showed the mass of the object to be about 4.1 million solar masses within a volume with radius no larger than 6.25 light-hours (45 AU \[6.7 billion km; 4.2 billion mi\]).[\[39\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Ghez08-40) S175 passed within a similar distance.[\[40\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-41) For comparison, the [Schwarzschild radius](https://en.wikipedia.org/wiki/Schwarzschild_radius "Schwarzschild radius") is 0.08 AU (12 million km; 7.4 million mi). They also determined the distance from Earth to the [Galactic Center](https://en.wikipedia.org/wiki/Galactic_Center "Galactic Center") (the rotational center of the Milky Way), which is important in calibrating astronomical distance scales, as 8,000 ± 600 [parsecs](https://en.wikipedia.org/wiki/Parsec "Parsec") (30,000 ± 2,000 [light-years](https://en.wikipedia.org/wiki/Light-year "Light-year")). In November 2004, a team of astronomers reported the discovery of a potential [intermediate-mass black hole](https://en.wikipedia.org/wiki/Intermediate-mass_black_hole "Intermediate-mass black hole"), referred to as [GCIRS 13E](https://en.wikipedia.org/wiki/GCIRS_13E "GCIRS 13E"), orbiting 3 light-years from Sagittarius A\*. This black hole of 1,300 solar masses is within a cluster of seven stars. This observation may add support to the idea that supermassive black holes grow by absorbing nearby smaller black holes and stars.\[*[citation needed](https://en.wikipedia.org/wiki/Wikipedia:Citation_needed "Wikipedia:Citation needed")*\] After monitoring stellar orbits around Sagittarius A\* for 16 years, Gillessen *et al.* estimated the object's mass at 4\.31±0\.38 million solar masses. The result was announced in 2008 and published in *[The Astrophysical Journal](https://en.wikipedia.org/wiki/The_Astrophysical_Journal "The Astrophysical Journal")* in 2009.[\[41\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Gillessen-42) [Reinhard Genzel](https://en.wikipedia.org/wiki/Reinhard_Genzel "Reinhard Genzel"), team leader of the research, said the study has delivered "what is now considered to be the best empirical evidence that supermassive black holes do really exist. The stellar orbits in the Galactic Center show that the central mass concentration of four million solar masses must be a black hole, beyond any reasonable doubt."[\[42\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-43) On January 5, 2015, NASA reported observing an [X-ray](https://en.wikipedia.org/wiki/X-ray "X-ray") flare 400 times brighter than usual, a record-breaker, from Sgr A\*. The unusual event may have been caused by the breaking apart of an [asteroid](https://en.wikipedia.org/wiki/Asteroid "Asteroid") falling into the black hole or by the entanglement of [magnetic field](https://en.wikipedia.org/wiki/Magnetic_field "Magnetic field") lines within gas flowing into Sgr A\*, according to astronomers.[\[43\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-NASA-20150105-44) On 13 May 2019, astronomers using the [Keck Observatory](https://en.wikipedia.org/wiki/Keck_Observatory "Keck Observatory") witnessed a sudden brightening of Sgr A\*, which became 75 times brighter than usual, suggesting that the supermassive black hole may have encountered another object.[\[44\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-45) In June 2023, unexplained filaments of [radio](https://en.wikipedia.org/wiki/Radio_wave "Radio wave") energy were found associated with Sagittarius A\*.[\[45\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-NYT-20230608-46) - [![ALMA observations of molecular-hydrogen-rich gas clouds, with the area around Sagittarius A\* circled\[46\]](https://upload.wikimedia.org/wikipedia/commons/thumb/a/ab/Cloudlets_swarm_around_our_local_supermassive_black_hole.tif/lossy-page1-250px-Cloudlets_swarm_around_our_local_supermassive_black_hole.tif.jpg)](https://en.wikipedia.org/wiki/File:Cloudlets_swarm_around_our_local_supermassive_black_hole.tif "ALMA observations of molecular-hydrogen-rich gas clouds, with the area around Sagittarius A* circled[46]") [ALMA](https://en.wikipedia.org/wiki/Atacama_Large_Millimeter_Array "Atacama Large Millimeter Array") observations of molecular-hydrogen-rich gas clouds, with the area around Sagittarius A\* circled[\[46\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-47) - [![An unusually bright X-ray flare from Sgr A\* was detected in 2013.\[43\]](https://upload.wikimedia.org/wikipedia/commons/thumb/8/85/X-RayFlare-BlackHole-MilkyWay-20140105.jpg/330px-X-RayFlare-BlackHole-MilkyWay-20140105.jpg)](https://en.wikipedia.org/wiki/File:X-RayFlare-BlackHole-MilkyWay-20140105.jpg "An unusually bright X-ray flare from Sgr A* was detected in 2013.[43]") An unusually bright [X-ray](https://en.wikipedia.org/wiki/X-ray "X-ray") flare from Sgr A\* was detected in 2013.[\[43\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-NASA-20150105-44) - [![Supernova remnant ejecta producing planet-forming material seen in radio and X-ray](https://upload.wikimedia.org/wikipedia/commons/thumb/1/19/15-044a-SuperNovaRemnant-PlanetFormation-SOFIA-20150319.jpg/330px-15-044a-SuperNovaRemnant-PlanetFormation-SOFIA-20150319.jpg)](https://en.wikipedia.org/wiki/File:15-044a-SuperNovaRemnant-PlanetFormation-SOFIA-20150319.jpg "Supernova remnant ejecta producing planet-forming material seen in radio and X-ray") [Supernova remnant](https://en.wikipedia.org/wiki/Supernova_remnant "Supernova remnant") ejecta producing planet-forming material seen in radio and X-ray - [![Supernova remnant ejecta producing planet-forming material seen in infrared and X-ray](https://upload.wikimedia.org/wikipedia/commons/thumb/0/01/15-044b-SuperNovaRemnant-PlanetFormation-SOFIA-20150319.jpg/330px-15-044b-SuperNovaRemnant-PlanetFormation-SOFIA-20150319.jpg)](https://en.wikipedia.org/wiki/File:15-044b-SuperNovaRemnant-PlanetFormation-SOFIA-20150319.jpg "Supernova remnant ejecta producing planet-forming material seen in infrared and X-ray") Supernova remnant ejecta producing planet-forming material seen in infrared and X-ray ## Central black hole \[[edit](https://en.wikipedia.org/w/index.php?title=Sagittarius_A*&action=edit&section=3 "Edit section: Central black hole")\] [![](https://upload.wikimedia.org/wikipedia/commons/thumb/6/63/Pointing_X-ray_Eyes_at_our_Resident_Supermassive_Black_Hole.jpg/330px-Pointing_X-ray_Eyes_at_our_Resident_Supermassive_Black_Hole.jpg)](https://en.wikipedia.org/wiki/File:Pointing_X-ray_Eyes_at_our_Resident_Supermassive_Black_Hole.jpg) [NuSTAR](https://en.wikipedia.org/wiki/NuSTAR "NuSTAR") has captured these first, focused views of the supermassive black hole at the heart of the Milky Way in high-energy X-rays. In a paper published on October 31, 2018, the discovery of conclusive evidence that Sagittarius A\* is a black hole was announced. Using the [GRAVITY](https://en.wikipedia.org/wiki/List_of_instruments_at_the_Very_Large_Telescope "List of instruments at the Very Large Telescope") [interferometer](https://en.wikipedia.org/wiki/Interferometry "Interferometry") and the four telescopes of the [Very Large Telescope](https://en.wikipedia.org/wiki/Very_Large_Telescope "Very Large Telescope") (VLT) to create a virtual telescope 130 metres (430 feet) in diameter, astronomers detected clumps of gas moving at about 30% of the speed of light. Emission from highly energetic electrons very close to the black hole was visible as three prominent bright flares. These exactly match theoretical predictions for hot spots orbiting close to a black hole of four million solar masses. The flares are thought to originate from magnetic interactions in the very hot gas orbiting very close to Sagittarius A\*.[\[12\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-DetectionOfBlackHoleSrgA-12)[\[47\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-ESO-48) In July 2018, it was reported that [S2](https://en.wikipedia.org/wiki/S2_\(star\) "S2 (star)") orbiting Sgr A\* had been recorded at 7,650 km/s (17.1 million mph), or 2.55% the [speed of light](https://en.wikipedia.org/wiki/Speed_of_light "Speed of light"), leading up to the [pericenter](https://en.wikipedia.org/wiki/Apsis#Terminology "Apsis") approach, in May 2018, at about 120 [AU](https://en.wikipedia.org/wiki/Astronomical_unit "Astronomical unit") (18 [billion](https://en.wikipedia.org/wiki/1000000000_\(number\) "1000000000 (number)") [km](https://en.wikipedia.org/wiki/Kilometre "Kilometre"); 11 billion [mi](https://en.wikipedia.org/wiki/Mile "Mile")) (approximately 1,400 [Schwarzschild radii](https://en.wikipedia.org/wiki/Schwarzschild_radius "Schwarzschild radius")) from Sgr A\*. At that close distance to the black hole, [Einstein](https://en.wikipedia.org/wiki/Albert_Einstein "Albert Einstein")'s theory of [general relativity](https://en.wikipedia.org/wiki/General_relativity "General relativity") predicts that S2 would show a discernible [gravitational redshift](https://en.wikipedia.org/wiki/Gravitational_redshift "Gravitational redshift") in addition to the usual velocity redshift. The gravitational redshift was detected, in agreement with the general relativity prediction within the 10 percent measurement precision.[\[48\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-aa33718-18-49)[\[49\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-2017-07-26_TG-50) The Sagittarius A\* radio emissions are not centered on the black hole, but arise from a bright spot in the region around the black hole, close to the [event horizon](https://en.wikipedia.org/wiki/Event_horizon "Event horizon"), possibly in the [accretion disc](https://en.wikipedia.org/wiki/Accretion_disk "Accretion disk"), or a [relativistic jet](https://en.wikipedia.org/wiki/Relativistic_jet "Relativistic jet") of material ejected from the disc.[\[50\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-EHS-51) If the apparent position of Sagittarius A\* were exactly centered on the black hole, it would be possible to see it magnified beyond its size, because of [gravitational lensing](https://en.wikipedia.org/wiki/Gravitational_lens "Gravitational lens") of the black hole. According to [general relativity](https://en.wikipedia.org/wiki/General_relativity "General relativity"), this would result in a ring-like structure, which has a diameter about 5.2 times the black hole's [Schwarzschild radius](https://en.wikipedia.org/wiki/Schwarzschild_radius "Schwarzschild radius") (10 ÎŒas). For a black hole of around 4 million solar masses, this corresponds to a size of approximately 52 [ÎŒas](https://en.wikipedia.org/wiki/%CE%9Cas "Μas"), which is consistent with the observed overall size of about 50 ÎŒas,[\[50\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-EHS-51) the size (apparent diameter) of the black hole Sgr A\* itself being 20 ÎŒas. Lower resolution observations revealed that the radio source of Sagittarius A\* is symmetrical.[\[51\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Issaoun-52) Simulations of alternative theories of gravity depict results that may be difficult to distinguish from GR.[\[52\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-53) A 2018 paper predicted an image of Sagittarius A\* that is in agreement with observations. In particular, it explains the small angular size and the symmetrical morphology of the source.[\[53\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-54) The mass of Sagittarius A\* has been estimated in two different ways: 1. Two groups—in Germany and the U.S.—monitored the orbits of individual stars very near to the black hole and used [Kepler's laws](https://en.wikipedia.org/wiki/Kepler%27s_laws "Kepler's laws") to infer the enclosed mass. The German group found a mass of 4\.31±0\.38 million solar masses,[\[41\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Gillessen-42) whereas the American group found 4\.1±0\.6 million solar masses.[\[39\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Ghez08-40) Given that this mass is confined inside a 44-million-kilometre-diameter sphere, this yields a density ten times higher than previous estimates.\[*[citation needed](https://en.wikipedia.org/wiki/Wikipedia:Citation_needed "Wikipedia:Citation needed")*\] 2. More recently, measurement of the [proper motions](https://en.wikipedia.org/wiki/Proper_motion "Proper motion") of a sample of several thousand stars within approximately one parsec from the black hole, combined with a [statistical technique](https://en.wikipedia.org/wiki/Leonard%E2%80%93Merritt_mass_estimator "Leonard–Merritt mass estimator"), has yielded both an estimate of the black hole's mass at 3\.6\+0.2 −0.4×106 M ☉, plus a distributed mass in the central parsec amounting to (1±0\.5)×106 M ☉.[\[54\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-55) The latter is thought to be composed of stars and [stellar remnants](https://en.wikipedia.org/wiki/Stellar_remnant "Stellar remnant").\[*[citation needed](https://en.wikipedia.org/wiki/Wikipedia:Citation_needed "Wikipedia:Citation needed")*\] [![](https://upload.wikimedia.org/wikipedia/commons/thumb/d/d3/Magnetar-SGR1745-2900-20150515.jpg/250px-Magnetar-SGR1745-2900-20150515.jpg)](https://en.wikipedia.org/wiki/File:Magnetar-SGR1745-2900-20150515.jpg) [Magnetar](https://en.wikipedia.org/wiki/Magnetar "Magnetar") found very close to the [supermassive black hole](https://en.wikipedia.org/wiki/Supermassive_black_hole "Supermassive black hole"), Sagittarius A\*, at the center of the Milky Way galaxy The comparatively small mass of this [supermassive black hole](https://en.wikipedia.org/wiki/Supermassive_black_hole "Supermassive black hole"), along with the low luminosity of the radio and infrared emission lines, imply that the Milky Way is not a [Seyfert galaxy](https://en.wikipedia.org/wiki/Seyfert_galaxy "Seyfert galaxy").[\[27\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Osterbrock-28) Ultimately, what is seen is not the black hole itself, but observations that are consistent only if there is a black hole present near Sgr A\*. In the case of such a black hole, the observed radio and infrared energy emanates from gas and dust heated to millions of degrees while falling into the black hole.[\[12\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-DetectionOfBlackHoleSrgA-12) The black hole itself is thought to emit only [Hawking radiation](https://en.wikipedia.org/wiki/Hawking_radiation "Hawking radiation") at a negligible temperature, on the order of 10−14 [kelvin](https://en.wikipedia.org/wiki/Kelvin "Kelvin").\[*[citation needed](https://en.wikipedia.org/wiki/Wikipedia:Citation_needed "Wikipedia:Citation needed")*\] The [European Space Agency](https://en.wikipedia.org/wiki/European_Space_Agency "European Space Agency")'s [gamma-ray](https://en.wikipedia.org/wiki/Gamma-ray "Gamma-ray") observatory [INTEGRAL](https://en.wikipedia.org/wiki/INTEGRAL "INTEGRAL") observed gamma rays interacting with the nearby [giant molecular cloud](https://en.wikipedia.org/wiki/Giant_molecular_cloud "Giant molecular cloud") [Sagittarius B2](https://en.wikipedia.org/wiki/Sagittarius_B2 "Sagittarius B2"), causing X-ray emission from the cloud. The total luminosity from this outburst (*L*≈1,5×1039 erg/s) is estimated to be a million times stronger than the current output from Sgr A\* and is comparable with a typical [active galactic nucleus](https://en.wikipedia.org/wiki/Active_galactic_nucleus "Active galactic nucleus").[\[55\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-hubble050127-56)[\[56\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-revnivtsev2004-57) In 2011 this conclusion was supported by Japanese astronomers observing the Milky Way's center with the *[Suzaku](https://en.wikipedia.org/wiki/Suzaku_\(satellite\) "Suzaku (satellite)")* satellite.[\[57\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-nobukawa2011-58) In July 2019, astronomers reported finding a star, [S5-HVS1](https://en.wikipedia.org/wiki/S5-HVS1 "S5-HVS1"), traveling 1,755 km/s (3.93 million mph) or 0.006 *c*. The star is in the [Grus](https://en.wikipedia.org/wiki/Grus_\(constellation\) "Grus (constellation)") (or Crane) [constellation](https://en.wikipedia.org/wiki/Constellation "Constellation") in the southern sky, and about 29,000 light-years from Earth, and may have been propelled out of the [Milky Way](https://en.wikipedia.org/wiki/Milky_Way "Milky Way") [galaxy](https://en.wikipedia.org/wiki/Galaxy "Galaxy") after interacting with Sagittarius A\*.[\[58\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-NYT-20191114-59)[\[59\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-MNRAS-20191109-60) Several values[\[60\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-61)[\[61\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-:02-62) have been given for its spin parameter a ∗ \= c J G M 2 {\\displaystyle a\_{\*}={\\frac {cJ}{GM^{2}}}} ![{\\displaystyle a\_{\*}={\\frac {cJ}{GM^{2}}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/bb6b50a7a6320b77aa1016a31fed667855c0b718); some examples are Fragione & Loeb (2020) a ∗ \< 0\.1 {\\displaystyle a\_{\*}\<0.1} ![{\\displaystyle a\_{\*}\<0.1}](https://wikimedia.org/api/rest_v1/media/math/render/svg/5caea805df13ecdb0f468a13cfde9e3905da8cfa)[\[62\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-63)*,* Belanger et al. (2006) a ∗ ∌ 0\.22 {\\displaystyle a\_{\*}\\sim 0.22} ![{\\displaystyle a\_{\*}\\sim 0.22}](https://wikimedia.org/api/rest_v1/media/math/render/svg/8a71eca52c51efd1d812a9e0dd80d8d0e0fcf3fb),[\[63\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-64) Meyer et al. (2006) a ∗ \> 0\.4 {\\displaystyle a\_{\*}\>0.4} ![{\\displaystyle a\_{\*}\>0.4}](https://wikimedia.org/api/rest_v1/media/math/render/svg/970a4fff5d1decb07b2da845307f62c8bee1d1b1),[\[64\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-65) Genzel et al. (2003) a ∗ ∌ 0\.52 {\\displaystyle a\_{\*}\\sim 0.52} ![{\\displaystyle a\_{\*}\\sim 0.52}](https://wikimedia.org/api/rest_v1/media/math/render/svg/d0d7e4e45719dc21a120dbe45ab34674383ecf22),[\[65\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-66) Daly (2019) a ∗ \= 0\.93 ± 0\.15 {\\displaystyle a\_{\*}=0.93\\pm 0.15} ![{\\displaystyle a\_{\*}=0.93\\pm 0.15}](https://wikimedia.org/api/rest_v1/media/math/render/svg/3f6e61ddba8f03442b71e56298129d5dcd7c9398),[\[66\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-67) and Daly et al. (2023) a ∗ \= 0\.90 ± 0\.06 {\\displaystyle a\_{\*}=0.90\\pm 0.06} ![{\\displaystyle a\_{\*}=0.90\\pm 0.06}](https://wikimedia.org/api/rest_v1/media/math/render/svg/1ac7981d75faf23ee39294d909158d66a263acbe).[\[61\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-:02-62) Daly et al. (2023) also found that the ratio of the black hole rotational mass component to the irreducible mass component of Sgr A\* is M r o t / M i r r \= 0\.62 ± 0\.10 {\\displaystyle M\_{rot}/M\_{irr}=0.62\\pm 0.10} ![{\\displaystyle M\_{rot}/M\_{irr}=0.62\\pm 0.10}](https://wikimedia.org/api/rest_v1/media/math/render/svg/ebd5eb15903976409fa2d2f6f063bbda02ff1382), which indicates that the black hole is rotating with an angular velocity that is 0\.62 ± 0\.10 {\\displaystyle 0.62\\pm 0.10} ![{\\displaystyle 0.62\\pm 0.10}](https://wikimedia.org/api/rest_v1/media/math/render/svg/5eadf14e64dec9c59ba8238d0bc162bd55324385) of the maximum possible value, set by the speed of light.[\[61\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-:02-62) [\[67\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-:03-68) ## Orbiting stars \[[edit](https://en.wikipedia.org/w/index.php?title=Sagittarius_A*&action=edit&section=4 "Edit section: Orbiting stars")\] Main article: [Sagittarius A\* cluster](https://en.wikipedia.org/wiki/Sagittarius_A*_cluster "Sagittarius A* cluster") [![](https://upload.wikimedia.org/wikipedia/commons/thumb/c/c1/Galactic_centre_orbits.svg/250px-Galactic_centre_orbits.svg.png)](https://en.wikipedia.org/wiki/File:Galactic_centre_orbits.svg) Inferred orbits of six stars around supermassive black hole candidate Sagittarius A\* at the Milky Way's center[\[68\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Eisenhauer-69) [![](https://upload.wikimedia.org/wikipedia/commons/thumb/5/50/SgrA2018.gif/250px-SgrA2018.gif)](https://en.wikipedia.org/wiki/File:SgrA2018.gif) Stars moving around Sagittarius A\*, 20-year timelapse, ending in 2018[\[69\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-70)[\[70\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-:0-71) [![](https://upload.wikimedia.org/wikipedia/commons/thumb/c/c4/SgrA2021.gif/250px-SgrA2021.gif)](https://en.wikipedia.org/wiki/File:SgrA2021.gif) Stars moving around Sagittarius A\* as seen in 2021[\[71\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-72)[\[72\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-73)[\[73\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-74) There are a number of stars in close orbit around Sagittarius A\*, which are collectively known as "S stars".[\[74\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-75) These stars are observed primarily in [K band](https://en.wikipedia.org/wiki/K_band_\(infrared\) "K band (infrared)") infrared wavelengths, as interstellar dust drastically limits visibility in visible wavelengths. This is a rapidly changing field—in 2011, the orbits of the most prominent stars then known were plotted in the diagram at left, showing a comparison between their orbits and various orbits in the [Solar System](https://en.wikipedia.org/wiki/Solar_System "Solar System").[\[70\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-:0-71) Since then, [S62](https://en.wikipedia.org/wiki/S62_\(star\) "S62 (star)") was thought to approach even more closely than those stars,[\[75\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-apj-76) but later observations of the star have found this not to be the case.[\[76\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-p994-77) The high velocities and close approaches to the supermassive black hole makes these stars useful to establish limits on the physical dimensions of Sagittarius A\*, as well as to observe general relativity associated effects like periapse shift of their orbits. An active watch is maintained for the possibility of stars approaching the event horizon close enough to be disrupted, but none of these stars are expected to suffer that fate. As of 2020[\[update\]](https://en.wikipedia.org/w/index.php?title=Sagittarius_A*&action=edit), S4714 is the current record holder of closest approach to Sagittarius A\*, at about 12.6 AU (1.88 billion km), almost as close as Saturn gets to the Sun, traveling at about 8% of the speed of light. These figures given are approximate, the formal uncertainties being 12\.6±9\.3 AU and 23,928±8,840 km/s. Its orbital period is 12 years, but an extreme eccentricity of 0.985 gives it the close approach and high velocity.[\[77\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-78) An excerpt from a table of this cluster (see [Sagittarius A\* cluster](https://en.wikipedia.org/wiki/Sagittarius_A*_cluster "Sagittarius A* cluster")), featuring the most prominent members. In the below table, **id1** is the star's name in the Gillessen catalog and **id2** in the catalog of the University of California, Los Angeles. **a**, **e**, **i**, **Ω** and **ω** are standard [orbital elements](https://en.wikipedia.org/wiki/Orbital_elements "Orbital elements"), with **a** measured in [arcseconds](https://en.wikipedia.org/wiki/Arcsecond "Arcsecond"). **Tp** is the epoch of pericenter passage, **P** is the orbital period in years and **Kmag** is the infrared [K-band](https://en.wikipedia.org/wiki/K_band_\(infrared\) "K band (infrared)") [apparent magnitude](https://en.wikipedia.org/wiki/Apparent_magnitude "Apparent magnitude") of the star. **q** and **v** are the pericenter distance in [AU](https://en.wikipedia.org/wiki/Astronomical_unit "Astronomical unit") and pericenter speed in percent of the [speed of light](https://en.wikipedia.org/wiki/Speed_of_light "Speed of light").[\[78\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-naess-79) | id1 | id2 | a | e | i (°) | Ω (°) | ω (°) | Tp (yr) | P (yr) | Kmag | q (AU) | v (%c) | |---|---|---|---|---|---|---|---|---|---|---|---| | S1 | S0-1 | 0\.5950 | 0\.5560 | 119\.14 | 342\.04 | 122\.30 | 2001\.800 | 166\.0 | 14\.70 | 2160\.7 | 0\.55 | | [S2](https://en.wikipedia.org/wiki/S2_\(star\) "S2 (star)") | S0-2 | 0\.1251 | 0\.8843 | 133\.91 | 228\.07 | 66\.25 | 2018\.379 | 16\.1 | 13\.95 | 118\.4 | 2\.56 | | S8 | S0-4 | 0\.4047 | 0\.8031 | 74\.37 | 315\.43 | 346\.70 | 1983\.640 | 92\.9 | 14\.50 | 651\.7 | 1\.07 | | S12 | S0-19 | 0\.2987 | 0\.8883 | 33\.56 | 230\.10 | 317\.90 | 1995\.590 | 58\.9 | 15\.50 | 272\.9 | 1\.69 | | S13 | S0-20 | 0\.2641 | 0\.4250 | 24\.70 | 74\.50 | 245\.20 | 2004\.860 | 49\.0 | 15\.80 | 1242\.0 | 0\.69 | | S14 | S0-16 | 0\.2863 | 0\.9761 | 100\.59 | 226\.38 | 334\.59 | 2000\.120 | 55\.3 | 15\.70 | 56\.0 | 3\.83 | | S4714 | | 0\.102 | 0\.985 | 127\.7 | 129\.28 | 357\.25 | 2017\.29 | 12\.0 | 17\.7 | 12\.6 | 8\.0 | ## Discovery of G2 gas cloud on an accretion course \[[edit](https://en.wikipedia.org/w/index.php?title=Sagittarius_A*&action=edit&section=5 "Edit section: Discovery of G2 gas cloud on an accretion course")\] First noticed as something unusual in images of the center of the Milky Way in 2002,[\[79\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Matson-80) the gas cloud G2, which has a mass about three times that of Earth, was confirmed to be likely on a course taking it into the accretion zone of Sgr A\* in a paper published in *Nature* in 2012.[\[80\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Gillessen_2012_51%E2%80%9354-81) Predictions of its orbit suggested it would make its closest approach to the black hole (a [perinigricon](https://en.wikipedia.org/wiki/Apsis "Apsis")) in early 2014, when the cloud was at a distance of just over 3,000 times the radius of the event horizon (or ≈260 AU, 36 light-hours) from the black hole. G2 has been observed to be disrupting since 2009,[\[80\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Gillessen_2012_51%E2%80%9354-81) and was predicted by some to be completely destroyed by the encounter, which could have led to a significant brightening of X-ray and other emission from the black hole. Other astronomers suggested the gas cloud could be hiding a dim star, or a binary star merger product, which would hold it together against the tidal forces of Sgr A\*, allowing the ensemble to pass by without any effect.[\[81\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Witzel2014-82) In addition to the tidal effects on the cloud itself, it was proposed in May 2013[\[82\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Bartos-83) that, prior to its perinigricon, G2 might experience multiple close encounters with members of the black-hole and neutron-star populations thought to orbit near the Galactic Center, offering some insight to the region surrounding the supermassive black hole at the center of the Milky Way.[\[83\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Geometry-84) The average rate of accretion onto Sgr A\* is unusually small for a black hole of its mass[\[84\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-85) and is only detectable because it is so close to Earth. It was thought that the passage of G2 in 2013 might offer astronomers the chance to learn much more about how material accretes onto supermassive black holes. Several astronomical facilities observed this closest approach, with observations confirmed with [Chandra](https://en.wikipedia.org/wiki/Chandra_X-ray_Observatory "Chandra X-ray Observatory"), [XMM](https://en.wikipedia.org/wiki/XMM-Newton "XMM-Newton"), [VLA](https://en.wikipedia.org/wiki/Very_Large_Array "Very Large Array"), [INTEGRAL](https://en.wikipedia.org/wiki/INTEGRAL "INTEGRAL"), [Swift](https://en.wikipedia.org/wiki/Neil_Gehrels_Swift_Observatory "Neil Gehrels Swift Observatory"), [Fermi](https://en.wikipedia.org/wiki/Fermi_Gamma-ray_Space_Telescope "Fermi Gamma-ray Space Telescope") and requested at [VLT](https://en.wikipedia.org/wiki/Very_Large_Telescope "Very Large Telescope") and [Keck](https://en.wikipedia.org/wiki/W._M._Keck_Observatory "W. M. Keck Observatory").[\[85\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-86) Simulations of the passage were made before it happened by groups at [ESO](https://en.wikipedia.org/wiki/European_Southern_Observatory "European Southern Observatory")[\[86\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-87) and [Lawrence Livermore National Laboratory](https://en.wikipedia.org/wiki/Lawrence_Livermore_National_Laboratory "Lawrence Livermore National Laboratory") (LLNL).[\[87\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-88) As the cloud approached the black hole, [Daryl Haggard](https://en.wikipedia.org/wiki/Daryl_Haggard "Daryl Haggard") said, "It's exciting to have something that feels more like an experiment", and hoped that the interaction would produce effects that would provide new information and insights.[\[88\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-89) Nothing was observed during and after the closest approach of the cloud to the black hole, which was described as a lack of "fireworks" and a "flop".[\[89\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-nature140721-90) Astronomers from the UCLA Galactic Center Group published observations obtained on March 19 and 20, 2014, concluding that G2 was still intact (in contrast to predictions for a simple gas cloud hypothesis) and that the cloud was likely to have a central star.[\[81\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Witzel2014-82) An analysis published on July 21, 2014, based on observations by the [ESO](https://en.wikipedia.org/wiki/European_Southern_Observatory "European Southern Observatory")'s [Very Large Telescope](https://en.wikipedia.org/wiki/Very_Large_Telescope "Very Large Telescope") in Chile, concluded alternatively that the cloud, rather than being isolated, might be a dense clump within a continuous but thinner stream of matter, and would act as a constant breeze on the disk of matter orbiting the black hole, rather than sudden gusts that would have caused high brightness as they hit, as originally expected. Supporting this hypothesis, G1, a cloud that passed near the black hole 13 years ago, had an orbit almost identical to G2, consistent with both clouds, and a gas tail thought to be trailing G2, all being denser clumps within a large single gas stream.[\[89\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-nature140721-90)[\[90\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-91) [Andrea Ghez](https://en.wikipedia.org/wiki/Andrea_M._Ghez "Andrea M. Ghez") et al. suggested in 2014 that G2 is not a gas cloud but rather a pair of binary stars that had been orbiting the black hole in tandem and merged into an extremely large star.[\[81\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Witzel2014-82)[\[91\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-92) [![](https://upload.wikimedia.org/wikipedia/commons/thumb/3/33/A_simulation_of_how_a_gas_cloud_that_has_been_observed_approaching_the_supermassive_black_hole_at_the_centre_of_the_galaxy.jpg/250px-A_simulation_of_how_a_gas_cloud_that_has_been_observed_approaching_the_supermassive_black_hole_at_the_centre_of_the_galaxy.jpg)](https://en.wikipedia.org/wiki/File:A_simulation_of_how_a_gas_cloud_that_has_been_observed_approaching_the_supermassive_black_hole_at_the_centre_of_the_galaxy.jpg) Artist impression of the accretion of gas cloud G2 onto Sgr A\*. Credit: ESO[\[92\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-93) This simulation shows a gas cloud, discovered in 2011, as it passes close to the supermassive black hole at the center of the Milky Way. This video sequence shows the motion of the dusty cloud G2 as it closes in on, and then passes, the supermassive black hole at the center of the Milky Way. ## See also \[[edit](https://en.wikipedia.org/w/index.php?title=Sagittarius_A*&action=edit&section=6 "Edit section: See also")\] - [Galactic Center GeV excess](https://en.wikipedia.org/wiki/Galactic_Center_GeV_excess "Galactic Center GeV excess") – Unexplained gamma rays from the Galactic Center - [List of nearest known black holes](https://en.wikipedia.org/wiki/List_of_nearest_known_black_holes "List of nearest known black holes") - [M87\*](https://en.wikipedia.org/wiki/Messier_87#Supermassive_black_hole_M87* "Messier 87") ## Notes \[[edit](https://en.wikipedia.org/w/index.php?title=Sagittarius_A*&action=edit&section=7 "Edit section: Notes")\] 1. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-dc1_21-0)** This roughly equates to around 37 times the diameter of the Sun at ~1,400,000 kilometers (~865,000 miles). ## References \[[edit](https://en.wikipedia.org/w/index.php?title=Sagittarius_A*&action=edit&section=8 "Edit section: References")\] 1. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-1)** [Reid and Brunthaler 2004](https://en.wikipedia.org/wiki/Sagittarius_A*#Reid) 2. ^ [***a***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-GRAVITY_2-0) [***b***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-GRAVITY_2-1) [***c***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-GRAVITY_2-2) [***d***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-GRAVITY_2-3) The GRAVITY collaboration (September 2023). ["Polarimetry and astrometry of NIR flares as event horizon scale, dynamical probes for the mass of Sgr A\*"](https://www.aanda.org/articles/aa/full_html/2023/09/aa47416-23/aa47416-23.html). *Astronomy & Astrophysics*. **677**: L10. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[2307\.11821](https://arxiv.org/abs/2307.11821). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2023A\&A...677L..10G](https://ui.adsabs.harvard.edu/abs/2023A&A...677L..10G). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1051/0004-6361/202347416](https://doi.org/10.1051%2F0004-6361%2F202347416). 3. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-3)** ["Astronomers reveal first image of the black hole at the heart of our galaxy"](https://eventhorizontelescope.org/blog/astronomers-reveal-first-image-black-hole-heart-our-galaxy). *Event Horizon Telescope*. May 12, 2022. [Archived](https://web.archive.org/web/20220512132514/https://eventhorizontelescope.org/blog/astronomers-reveal-first-image-black-hole-heart-our-galaxy) from the original on May 12, 2022. Retrieved May 12, 2022. 4. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-4)** Parsons, Jeff (October 31, 2018). ["Scientists find proof a supermassive black hole is lurking at the centre of the Milky Way"](https://metro.co.uk/2018/10/31/scientists-find-proof-a-supermassive-black-hole-is-lurking-at-the-centre-of-the-milky-way-8092994/). *Metro*. [Archived](https://web.archive.org/web/20181031214911/https://metro.co.uk/2018/10/31/scientists-find-proof-a-supermassive-black-hole-is-lurking-at-the-centre-of-the-milky-way-8092994/) from the original on October 31, 2018. Retrieved October 31, 2018. 5. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-5)** Mosher, Dave (October 31, 2018). ["A 'mind-boggling' telescope observation has revealed the point of no return for our galaxy's monster black hole"](https://web.archive.org/web/20181031144008/https://www.middletownpress.com/technology/businessinsider/article/Supermassive-black-holes-gorge-themselves-on-a-7971243.php). *The Middletown Press*. Business Insider. Archived from [the original](https://www.middletownpress.com/technology/businessinsider/article/Supermassive-black-holes-gorge-themselves-on-a-7971243.php) on October 31, 2018. Retrieved May 16, 2022. 6. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-plait_6-0)** [Plait, Phil](https://en.wikipedia.org/wiki/Phil_Plait "Phil Plait") (November 7, 2018). ["Astronomers See Material Orbiting a Black Hole \*Right\* at the Edge of Forever"](https://www.syfy.com/syfywire/astronomers-see-material-orbiting-a-black-hole-right-at-the-edge-of-forever). *Bad Astronomy*. Syfy Wire. [Archived](https://web.archive.org/web/20181110143143/https://www.syfy.com/syfywire/astronomers-see-material-orbiting-a-black-hole-right-at-the-edge-of-forever) from the original on November 10, 2018. Retrieved November 12, 2018. 7. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-7)** Calculated using [Equatorial and Ecliptic Coordinates](https://frostydrew.org/utilities.dc/convert/tool-eq_coordinates/pss-fdo/) [Archived](https://web.archive.org/web/20190721134008/https://frostydrew.org/utilities.dc/convert/tool-eq_coordinates/pss-fdo/) July 21, 2019, at the [Wayback Machine](https://en.wikipedia.org/wiki/Wayback_Machine "Wayback Machine") calculator 8. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-8)** Sutter, Paul (May 20, 2022). ["How did astronomers take a picture of our galaxy's supermassive black hole?"](https://www.astronomy.com/science/how-did-astronomers-take-a-picture-of-our-galaxys-supermassive-black-hole/). *Astronomy Magazine*. Retrieved April 16, 2025. "The Event Horizon Telescope (EHT) collaboration released the first ever image of the accretion disk around the Milky Way's supermassive black hole, Sagittarius A\* (Sgr A\*), on May 12, 2022." 9. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-AJ-202205_9-0)** Bower, Geoffrey C. (May 2022). ["Focus on First Sgr A\* Results from the Event Horizon Telescope"](https://iopscience.iop.org/journal/2041-8205/page/Focus_on_First_Sgr_A_Results). *[The Astrophysical Journal](https://en.wikipedia.org/wiki/The_Astrophysical_Journal "The Astrophysical Journal")*. [Archived](https://web.archive.org/web/20220719162915/https://iopscience.iop.org/journal/2041-8205/page/Focus_on_First_Sgr_A_Results) from the original on July 19, 2022. Retrieved May 12, 2022. 10. ^ [***a***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-ESO2208_10-0) [***b***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-ESO2208_10-1) ["Astronomers reveal first image of the black hole at the heart of our galaxy"](https://www.eso.org/public/news/eso2208-eht-mw/). *eso.org*. May 12, 2022. [Archived](https://web.archive.org/web/20220512130910/https://www.eso.org/public/news/eso2208-eht-mw/) from the original on May 12, 2022. Retrieved May 12, 2022. 11. ^ [***a***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-NYT-20220512_11-0) [***b***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-NYT-20220512_11-1) Overbye, Dennis (May 12, 2022). ["The Milky Way's Black Hole Comes to Light"](https://www.nytimes.com/2022/05/12/science/black-hole-photo.html). *[The New York Times](https://en.wikipedia.org/wiki/The_New_York_Times "The New York Times")*. [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0362-4331](https://search.worldcat.org/issn/0362-4331). [Archived](https://web.archive.org/web/20220512040455/https://www.nytimes.com/2022/05/12/science/black-hole-photo.html/) from the original on May 12, 2022. Retrieved May 12, 2022. 12. ^ [***a***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-DetectionOfBlackHoleSrgA_12-0) [***b***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-DetectionOfBlackHoleSrgA_12-1) [***c***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-DetectionOfBlackHoleSrgA_12-2) Abuter, R.; Amorim, A.; Bauböck, M.; Berger, J. P.; Bonnet, H.; Brandner, W.; ClĂ©net, Y.; CoudĂ© Du Foresto, V.; De Zeeuw, P. T.; Deen, C.; Dexter, J.; Duvert, G.; Eckart, A.; Eisenhauer, F.; [Förster Schreiber, N. M.](https://en.wikipedia.org/wiki/Natascha_F%C3%B6rster_Schreiber "Natascha Förster Schreiber"); Garcia, P.; Gao, F.; Gendron, E.; Genzel, R.; Gillessen, S.; Guajardo, P.; Habibi, M.; Haubois, X.; Henning, T.; Hippler, S.; Horrobin, M.; Huber, A.; JimĂ©nez Rosales, A.; Jocou, L.; et al. (2018). "Detection of orbital motions near the last stable circular orbit of the massive black hole SgrA". *Astronomy & Astrophysics*. **618**: L10. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[1810\.12641](https://arxiv.org/abs/1810.12641). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2018A\&A...618L..10G](https://ui.adsabs.harvard.edu/abs/2018A&A...618L..10G). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1051/0004-6361/201834294](https://doi.org/10.1051%2F0004-6361%2F201834294). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [53613305](https://api.semanticscholar.org/CorpusID:53613305). 13. ^ [***a***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Intense_sub-arcsecond_structure_in_13-0) [***b***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Intense_sub-arcsecond_structure_in_13-1) Balick, B.; Brown, R. L. (December 1, 1974). ["Intense sub-arcsecond structure in the galactic center"](https://doi.org/10.1086%2F153242). *Astrophysical Journal*. **194** (1): 265–270\. [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[1974ApJ...194..265B](https://ui.adsabs.harvard.edu/abs/1974ApJ...194..265B). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1086/153242](https://doi.org/10.1086%2F153242). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [121802758](https://api.semanticscholar.org/CorpusID:121802758). 14. ^ [***a***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Melia_2007,_p._7_14-0) [***b***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Melia_2007,_p._7_14-1) [Melia 2007](https://en.wikipedia.org/wiki/Sagittarius_A*#Melia), p. 7 15. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-15)** Brown, Robert L. (November 1, 1982). ["Precessing Jets in Sagittarius A: Gas Dynamics in the Central Parsec of the Galaxy"](https://doi.org/10.1086%2F160401). *The Astrophysical Journal*. **262**: 110–119\. [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[1982ApJ...262..110B](https://ui.adsabs.harvard.edu/abs/1982ApJ...262..110B). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1086/160401](https://doi.org/10.1086%2F160401). 16. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Henderson_16-0)** Henderson, Mark (December 9, 2009). ["Astronomers confirm black hole at the heart of the Milky Way"](https://web.archive.org/web/20081216235509/http://www.timesonline.co.uk/tol/news/uk/science/article5316001.ece). Times Online. Archived from [the original](http://www.timesonline.co.uk/tol/news/uk/science/article5316001.ece) on December 16, 2008. Retrieved June 6, 2019. 17. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-17)** ["The Nobel Prize in Physics 2020"](https://www.nobelprize.org/prizes/physics/2020/summary/). October 6, 2020. [Archived](https://web.archive.org/web/20210424115309/https://www.nobelprize.org/prizes/physics/2020/summary/) from the original on April 24, 2021. Retrieved October 7, 2020. 18. ^ [***a***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Shadow_18-0) [***b***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Shadow_18-1) The Event Horizon Telescope Collaboration (May 1, 2022). ["First Sagittarius A\* Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole in the Center of the Milky Way"](https://doi.org/10.3847%2F2041-8213%2Fac6674). *The Astrophysical Journal Letters*. **930** (2): L12. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[2311\.08680](https://arxiv.org/abs/2311.08680). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2022ApJ...930L..12E](https://ui.adsabs.harvard.edu/abs/2022ApJ...930L..12E). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.3847/2041-8213/ac6674](https://doi.org/10.3847%2F2041-8213%2Fac6674). [eISSN](https://en.wikipedia.org/wiki/EISSN_\(identifier\) "EISSN (identifier)") [2041-8213](https://search.worldcat.org/issn/2041-8213). [hdl](https://en.wikipedia.org/wiki/Hdl_\(identifier\) "Hdl (identifier)"):[10261/278882](https://hdl.handle.net/10261%2F278882). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [2041-8205](https://search.worldcat.org/issn/2041-8205). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [248744791](https://api.semanticscholar.org/CorpusID:248744791). 19. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-19)** Hensley, Kerry (May 12, 2022). ["First Image of the Milky Way's Supermassive Black Hole"](https://aasnova.org/2022/05/12/first-image-of-the-milky-ways-supermassive-black-hole/). *AAS Nova*. [Archived](https://web.archive.org/web/20220802102347/https://aasnova.org/2022/05/12/first-image-of-the-milky-ways-supermassive-black-hole/) from the original on August 2, 2022. Retrieved May 13, 2022. 20. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-20)** The Event Horizon Telescope Collaboration (May 1, 2022). ["First Sagittarius A\* Event Horizon Telescope Results. III. Imaging of the Galactic Center Supermassive Black Hole"](https://doi.org/10.3847%2F2041-8213%2Fac6429). *The Astrophysical Journal Letters*. **930** (2): L14. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[2311\.09479](https://arxiv.org/abs/2311.09479). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2022ApJ...930L..14E](https://ui.adsabs.harvard.edu/abs/2022ApJ...930L..14E). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.3847/2041-8213/ac6429](https://doi.org/10.3847%2F2041-8213%2Fac6429). [eISSN](https://en.wikipedia.org/wiki/EISSN_\(identifier\) "EISSN (identifier)") [2041-8213](https://search.worldcat.org/issn/2041-8213). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [2041-8205](https://search.worldcat.org/issn/2041-8205). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [248744704](https://api.semanticscholar.org/CorpusID:248744704). 21. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-22)** [Backer and Sramek 1999](https://en.wikipedia.org/wiki/Sagittarius_A*#Backer), § 3 22. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-23)** ["Focus on the First Event Horizon Telescope Results – The Astrophysical Journal Letters – IOPscience"](https://iopscience.iop.org/journal/2041-8205/page/Focus_on_EHT). *iopscience.iop.org*. [Archived](https://web.archive.org/web/20190514171744/https://iopscience.iop.org/journal/2041-8205/page/Focus_on_EHT) from the original on May 14, 2019. Retrieved April 10, 2019. 23. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-24)** Overbye, Dennis (April 10, 2019). ["Black Hole Picture Revealed for the First Time"](https://www.nytimes.com/2019/04/10/science/black-hole-picture.html). *The New York Times*. [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0362-4331](https://search.worldcat.org/issn/0362-4331). [Archived](https://web.archive.org/web/20190521020231/https://www.nytimes.com/2019/04/10/science/black-hole-picture.html) from the original on May 21, 2019. Retrieved April 10, 2019. 24. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-25)** ["HAWC+, the Far-Infrared Camera and Polarimeter for SOFIA"](https://www.sofia.usra.edu/science/instruments/hawc). 2018. [Archived](https://web.archive.org/web/20210803210336/https://www.sofia.usra.edu/science/instruments/hawc) from the original on August 3, 2021. Retrieved August 3, 2021. 25. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-26)** ["The Milky Way's Monster Black Hole Has a Cool Gas Halo – Literally"](https://www.space.com/milky-way-monster-black-hole-cool-disk.html). *Space.com*. June 5, 2019. [Archived](https://web.archive.org/web/20190619004814/https://www.space.com/milky-way-monster-black-hole-cool-disk.html) from the original on June 19, 2019. Retrieved June 19, 2019. 26. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-27)** ["Magnetic Fields May Muzzle Milky Way's Monster Black Hole"](https://www.space.com/milky-way-supermassive-black-hole-magnetic-field-quiet.html). *Space.com*. June 14, 2019. [Archived](https://web.archive.org/web/20190618050808/https://www.space.com/milky-way-supermassive-black-hole-magnetic-field-quiet.html) from the original on June 18, 2019. Retrieved June 19, 2019. 27. ^ [***a***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Osterbrock_28-0) [***b***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Osterbrock_28-1) [Osterbrock and Ferland 2006](https://en.wikipedia.org/wiki/Sagittarius_A*#Osterbrock), p. 390 28. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-29)** ["Karl Jansky: The Father of Radio Astronomy"](https://armaghplanet.com/karl-jansky-the-father-of-radio-astronomy.html). August 29, 2012. [Archived](https://web.archive.org/web/20190628163259/http://www.armaghplanet.com/karl-jansky-the-father-of-radio-astronomy.html) from the original on June 28, 2019. Retrieved January 27, 2019. 29. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-goss_history_30-0)** Goss, W. M.; McGee, R. X. (1996). ["The Discovery of the Radio Source Sagittarius A (Sgr A)"](https://ui.adsabs.harvard.edu/abs/1996ASPC..102..369G/abstract). *The Galactic Center, Astronomical Society of the Pacific Conference Series*. **102**: 369. [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[1996ASPC..102..369G](https://ui.adsabs.harvard.edu/abs/1996ASPC..102..369G). [Archived](https://web.archive.org/web/20210303171739/https://ui.adsabs.harvard.edu/abs/1996ASPC..102..369G/abstract) from the original on March 3, 2021. Retrieved February 25, 2021. 30. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-piddington_31-0)** Piddington, J. H.; Minnett, H. C. (December 1, 1951). ["Observations of Galactic Radiation at Frequencies of 1200 and 3000 Mc/s"](https://ui.adsabs.harvard.edu/abs/1951AuSRA...4..459P/abstract). *Australian Journal of Scientific Research A*. **4** (4): 459. [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[1951AuSRA...4..459P](https://ui.adsabs.harvard.edu/abs/1951AuSRA...4..459P). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1071/CH9510459](https://doi.org/10.1071%2FCH9510459). [Archived](https://web.archive.org/web/20210413090955/https://ui.adsabs.harvard.edu/abs/1951AuSRA...4..459P/abstract) from the original on April 13, 2021. Retrieved February 25, 2021. 31. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-galactic_centre_mcgee_32-0)** McGee, R. X.; Bolton, J. G. (May 1, 1954). ["Probable observation of the galactic nucleus at 400 Mc./s"](https://ui.adsabs.harvard.edu/abs/1954Natur.173..985M/abstract). *Nature*. **173** (4412): 985–987\. [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[1954Natur.173..985M](https://ui.adsabs.harvard.edu/abs/1954Natur.173..985M). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1038/173985b0](https://doi.org/10.1038%2F173985b0). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0028-0836](https://search.worldcat.org/issn/0028-0836). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [4188235](https://api.semanticscholar.org/CorpusID:4188235). [Archived](https://web.archive.org/web/20220130113909/https://ui.adsabs.harvard.edu/abs/1954Natur.173..985M/abstract) from the original on January 30, 2022. Retrieved February 25, 2021. 32. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-33)** Goss, W. M.; Brown, Robert L.; Lo, K. Y. (May 6, 2003). "The Discovery of Sgr A\*". *Astronomische Nachrichten*. **324** (1): 497. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[astro-ph/0305074](https://arxiv.org/abs/astro-ph/0305074). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2003ANS...324..497G](https://ui.adsabs.harvard.edu/abs/2003ANS...324..497G). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1002/asna.200385047](https://doi.org/10.1002%2Fasna.200385047). 33. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-34)** Brown, R. L. (November 1, 1982). ["Precessing jets in Sagittarius A – Gas dynamics in the central parsec of the galaxy"](https://doi.org/10.1086%2F160401). *Astrophysical Journal, Part 1*. **262**: 110–119\. [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[1982ApJ...262..110B](https://ui.adsabs.harvard.edu/abs/1982ApJ...262..110B). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1086/160401](https://doi.org/10.1086%2F160401). 34. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-35)** Genzel, R; Hollenbach, D; Townes, C H (1994). "The nucleus of our Galaxy". *Reports on Progress in Physics*. **57** (5): 417–479\. [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[1994RPPh...57..417G](https://ui.adsabs.harvard.edu/abs/1994RPPh...57..417G). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1088/0034-4885/57/5/001](https://doi.org/10.1088%2F0034-4885%2F57%2F5%2F001). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0034-4885](https://search.worldcat.org/issn/0034-4885). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [250900662](https://api.semanticscholar.org/CorpusID:250900662). 35. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-36)** [Schödel *et al.* 2002](https://en.wikipedia.org/wiki/Sagittarius_A*#Schodel) 36. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-37)** Sakai, Shoko; Lu, Jessica R.; Ghez, Andrea; Jia, Siyao; Do, Tuan; Witzel, Gunther; Gautam, Abhimat K.; Hees, Aurelien; Becklin, E.; Matthews, K.; Hosek, M. W. (March 5, 2019). ["The Galactic Center: An Improved Astrometric Reference Frame for Stellar Orbits around the Supermassive Black Hole"](https://doi.org/10.3847%2F1538-4357%2Fab0361). *The Astrophysical Journal*. **873** (1): 65. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[1901\.08685](https://arxiv.org/abs/1901.08685). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2019ApJ...873...65S](https://ui.adsabs.harvard.edu/abs/2019ApJ...873...65S). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.3847/1538-4357/ab0361](https://doi.org/10.3847%2F1538-4357%2Fab0361). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [1538-4357](https://search.worldcat.org/issn/1538-4357). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [119331998](https://api.semanticscholar.org/CorpusID:119331998). 37. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-38)** ["Best View Yet of Dusty Cloud Passing Galactic Centre Black Hole"](http://www.eso.org/public/news/eso1512/). [Archived](https://web.archive.org/web/20150407034121/http://www.eso.org/public/news/eso1512/) from the original on April 7, 2015. Retrieved June 16, 2015. 38. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-39)** [Ghez *et al.* (2003) "The First Measurement of Spectral Lines in a Short-Period Star Bound to the Galaxy's Central Black Hole: A Paradox of Youth" Astrophysical Journal **586** L127](https://en.wikipedia.org/wiki/Sagittarius_A*#Ghez03) 39. ^ [***a***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Ghez08_40-0) [***b***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Ghez08_40-1) Ghez, A. M.; et al. (December 2008). "Measuring Distance and Properties of the Milky Way's Central Supermassive Black Hole with Stellar Orbits". *Astrophysical Journal*. **689** (2): 1044–1062\. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[0808\.2870](https://arxiv.org/abs/0808.2870). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2008ApJ...689.1044G](https://ui.adsabs.harvard.edu/abs/2008ApJ...689.1044G). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1086/592738](https://doi.org/10.1086%2F592738). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [18335611](https://api.semanticscholar.org/CorpusID:18335611). 40. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-41)** Gillessen, S.; Plewa, P. M.; Eisenhauer, F.; Sari, R.; Waisberg, I.; Habibi, M.; Pfuhl, O.; George, E.; Dexter, J. (2017). ["An Update on Monitoring Stellar Orbits in the Galactic Center"](https://doi.org/10.3847%2F1538-4357%2Faa5c41). *The Astrophysical Journal*. **837** (1): 30. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[1611\.09144](https://arxiv.org/abs/1611.09144). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2017ApJ...837...30G](https://ui.adsabs.harvard.edu/abs/2017ApJ...837...30G). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.3847/1538-4357/aa5c41](https://doi.org/10.3847%2F1538-4357%2Faa5c41). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0004-637X](https://search.worldcat.org/issn/0004-637X). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [119087402](https://api.semanticscholar.org/CorpusID:119087402). 41. ^ [***a***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Gillessen_42-0) [***b***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Gillessen_42-1) [Gillessen *et al.* 2009](https://en.wikipedia.org/wiki/Sagittarius_A*#Gillessen) 42. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-43)** [O'Neill 2008](https://en.wikipedia.org/wiki/Sagittarius_A*#ONeill) 43. ^ [***a***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-NASA-20150105_44-0) [***b***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-NASA-20150105_44-1) Chou, Felicia; Anderson, Janet; Watzke, Megan (January 5, 2015). ["NASA's Chandra Detects Record-Breaking Outburst from Milky Way's Black Hole"](https://www.nasa.gov/press/2015/january/nasa-s-chandra-detects-record-breaking-outburst-from-milky-way-s-black-hole/). [NASA](https://en.wikipedia.org/wiki/NASA "NASA"). [Archived](https://web.archive.org/web/20150106100532/http://www.nasa.gov/press/2015/january/nasa-s-chandra-detects-record-breaking-outburst-from-milky-way-s-black-hole/) from the original on January 6, 2015. Retrieved January 6, 2015. 44. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-45)** ["Our Galaxy's Supermassive Black Hole Has Emitted a Mysteriously Bright Flare"](https://www.sciencealert.com/our-galaxy-s-supermassive-black-hole-just-mysteriously-got-really-really-bright). *Science Alert*. August 12, 2019. [Archived](https://web.archive.org/web/20190812120201/https://www.sciencealert.com/our-galaxy-s-supermassive-black-hole-just-mysteriously-got-really-really-bright) from the original on August 12, 2019. Retrieved August 12, 2019. 45. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-NYT-20230608_46-0)** [Overbye, Dennis](https://en.wikipedia.org/wiki/Dennis_Overbye "Dennis Overbye") (June 8, 2023). ["Our Local Black Hole Serves Up an 'Awe Moment' – Filaments of radio energy from Sagittarius A\*, the black hole at the center of the Milky Way galaxy, are turning astronomers' heads"](https://www.nytimes.com/2023/06/08/science/astronomy-cosmos-black-hole.html). *[The New York Times](https://en.wikipedia.org/wiki/The_New_York_Times "The New York Times")*. Retrieved June 9, 2023. `{{cite news}}`: CS1 maint: deprecated archival service ([link](https://en.wikipedia.org/wiki/Category:CS1_maint:_deprecated_archival_service "Category:CS1 maint: deprecated archival service")) 46. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-47)** ["Cloudlets swarm around our local supermassive black hole"](https://www.eso.org/public/images/potw1843a/). *www.eso.org*. [Archived](https://web.archive.org/web/20181022093902/https://www.eso.org/public/images/potw1843a/) from the original on October 22, 2018. Retrieved October 22, 2018. 47. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-ESO_48-0)** ["Most Detailed Observations of Material Orbiting close to a Black Hole"](https://www.eso.org/public/news/eso1835/). *European Southern Observatory (ESO)*. [Archived](https://web.archive.org/web/20181101000741/https://www.eso.org/public/news/eso1835/) from the original on November 1, 2018. Retrieved November 1, 2018. 48. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-aa33718-18_49-0)** Genzel; et al. (July 26, 2018). ["Detection of the gravitational redshift in the orbit of the star S2 near the Galactic centre massive black hole"](https://www.aanda.org/articles/aa/full_html/2018/07/aa33718-18/aa33718-18.html). *Astronomy & Astrophysics*. **615**: L15. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[1807\.09409](https://arxiv.org/abs/1807.09409). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2018A\&A...615L..15G](https://ui.adsabs.harvard.edu/abs/2018A&A...615L..15G). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1051/0004-6361/201833718](https://doi.org/10.1051%2F0004-6361%2F201833718). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [118891445](https://api.semanticscholar.org/CorpusID:118891445). [Archived](https://web.archive.org/web/20190404120522/https://www.aanda.org/articles/aa/full_html/2018/07/aa33718-18/aa33718-18.html) from the original on April 4, 2019. Retrieved July 27, 2018. 49. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-2017-07-26_TG_50-0)** ["Star spotted speeding near black hole at centre of Milky Way – Chile's Very Large Telescope tracks S2 star as it reaches mind-boggling speeds by supermassive black hole"](https://www.theguardian.com/science/2018/jul/26/star-spotted-speeding-near-milky-way-black-hole-for-first-time). *The Guardian*. July 26, 2017. [Archived](https://web.archive.org/web/20190404100253/https://www.theguardian.com/science/2018/jul/26/star-spotted-speeding-near-milky-way-black-hole-for-first-time) from the original on April 4, 2019. Retrieved July 27, 2018. 50. ^ [***a***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-EHS_51-0) [***b***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-EHS_51-1) Lu, R.; et al. (2018). ["Detection of intrinsic source structure at ~3 Schwarzschild radii with Millimeter-VLBI observations of Sgr A\*"](https://doi.org/10.3847%2F1538-4357%2Faabe2e). *Astrophysical Journal*. **859** (1): 60. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[1805\.09223](https://arxiv.org/abs/1805.09223). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.3847/1538-4357/aabe2e](https://doi.org/10.3847%2F1538-4357%2Faabe2e). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [51917277](https://api.semanticscholar.org/CorpusID:51917277). 51. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Issaoun_52-0)** Issaoun, S. (January 18, 2019). ["The Size, Shape, and Scattering of Sagittarius A\* at 86 GHz: First VLBI with ALMA"](https://doi.org/10.3847%2F1538-4357%2Faaf732). *The Astrophysical Journal*. **871** (1): 30. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[1901\.06226](https://arxiv.org/abs/1901.06226). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2019ApJ...871...30I](https://ui.adsabs.harvard.edu/abs/2019ApJ...871...30I). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.3847/1538-4357/aaf732](https://doi.org/10.3847%2F1538-4357%2Faaf732). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [84180473](https://api.semanticscholar.org/CorpusID:84180473). 52. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-53)** Rezzolla, Luciano (April 17, 2018). ["Astrophysicists Test Theories of Gravity with Black Hole Shadows"](https://scitechdaily.com/astrophysicists-test-theories-of-gravity-with-black-hole-shadows/). *SciTech Daily*. [Archived](https://web.archive.org/web/20190402072150/https://scitechdaily.com/astrophysicists-test-theories-of-gravity-with-black-hole-shadows/) from the original on April 2, 2019. Retrieved April 2, 2019. 53. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-54)** ["Revealing the black hole at the heart of the galaxy"](https://www.phys.org/news/2019-01-revealing-black-hole-heart-galaxy.html). Netherlands Research School for Astronomy. January 22, 2019. [Archived](https://web.archive.org/web/20190318132949/https://phys.org/news/2019-01-revealing-black-hole-heart-galaxy.html) from the original on March 18, 2019. Retrieved April 2, 2019 – via [Phys.org](https://en.wikipedia.org/wiki/Phys.org "Phys.org"). 54. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-55)** [Schödel *et al.* 2009](https://en.wikipedia.org/wiki/Sagittarius_A*#Schodel2) 55. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-hubble050127_56-0)** ["Integral rolls back history of Milky Way's super-massive black hole"](http://www.esa.int/SPECIALS/Integral/SEMSKPO3E4E_0.html). Hubble News Desk. January 28, 2005. [Archived](https://web.archive.org/web/20121016202343/http://www.esa.int/SPECIALS/Integral/SEMSKPO3E4E_0.html) from the original on October 16, 2012. Retrieved October 31, 2007. 56. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-revnivtsev2004_57-0)** Revnivtsev, M. G.; et al. (October 2004). "Hard X-ray view of the past activity of Sgr A\$^{\\star}\$ in a natural Compton mirror". *[Astronomy & Astrophysics](https://en.wikipedia.org/wiki/Astronomy_%26_Astrophysics "Astronomy & Astrophysics")*. **425** (3): L49–L52. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[astro-ph/0408190](https://arxiv.org/abs/astro-ph/0408190). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2004A\&A...425L..49R](https://ui.adsabs.harvard.edu/abs/2004A&A...425L..49R). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1051/0004-6361:200400064](https://doi.org/10.1051%2F0004-6361%3A200400064). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0004-6361](https://search.worldcat.org/issn/0004-6361). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [18872302](https://api.semanticscholar.org/CorpusID:18872302). 57. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-nobukawa2011_58-0)** Nobukawa, M.; et al. (September 8, 2011). "New Evidence for High Activity of the Supermassive Black Hole in our Galaxy". *[The Astrophysical Journal](https://en.wikipedia.org/wiki/The_Astrophysical_Journal "The Astrophysical Journal")*. **739** (2): L52. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[1109\.1950](https://arxiv.org/abs/1109.1950). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2011ApJ...739L..52N](https://ui.adsabs.harvard.edu/abs/2011ApJ...739L..52N). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1088/2041-8205/739/2/L52](https://doi.org/10.1088%2F2041-8205%2F739%2F2%2FL52). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [2041-8205](https://search.worldcat.org/issn/2041-8205). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [119244398](https://api.semanticscholar.org/CorpusID:119244398). 58. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-NYT-20191114_59-0)** [Overbye, Dennis](https://en.wikipedia.org/wiki/Dennis_Overbye "Dennis Overbye") (November 14, 2019). ["A Black Hole Threw a Star Out of the Milky Way Galaxy – So long, S5-HVS1, we hardly knew you"](https://www.nytimes.com/2019/11/14/science/stars-black-hole-milky-way.html). *[The New York Times](https://en.wikipedia.org/wiki/The_New_York_Times "The New York Times")*. [Archived](https://web.archive.org/web/20191117223906/https://www.nytimes.com/2019/11/14/science/stars-black-hole-milky-way.html) from the original on November 17, 2019. Retrieved November 18, 2019. 59. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-MNRAS-20191109_60-0)** Koposov, Sergey E; et al. (January 11, 2020). ["Discovery of a nearby 1700 km s−1 star ejected from the Milky Way by Sgr A\*"](https://doi.org/10.1093%2Fmnras%2Fstz3081). *[Monthly Notices of the Royal Astronomical Society](https://en.wikipedia.org/wiki/Monthly_Notices_of_the_Royal_Astronomical_Society "Monthly Notices of the Royal Astronomical Society")*. **491** (2): 2465–2480\. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[1907\.11725](https://arxiv.org/abs/1907.11725). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1093/mnras/stz3081](https://doi.org/10.1093%2Fmnras%2Fstz3081). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0035-8711](https://search.worldcat.org/issn/0035-8711). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [198968336](https://api.semanticscholar.org/CorpusID:198968336). 60. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-61)** Eckart, Andreas; Tursunov, A.A.; Zajacek, M.; Parsa, M.; Hosseini, E.; Subroweit, M.; Peissker, F.; Straubmeier, C.; Horrobin, M.; Karas, V. (February 1, 2019). ["Mass, Distance, Spin, Charge, and Orientation of the super massive black hole SgrA\*"](https://pos.sissa.it/342/048). *Proceedings of Science*. **342**. Sissa Medialab: 048. [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.22323/1.342.0048](https://doi.org/10.22323%2F1.342.0048). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [189921901](https://api.semanticscholar.org/CorpusID:189921901). 61. ^ [***a***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-:02_62-0) [***b***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-:02_62-1) [***c***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-:02_62-2) Daly, Ruth A; Donahue, Megan; O'Dea, Christopher P; Sebastian, Biny; Haggard, Daryl; Lu, Anan (October 28, 2023). ["New black hole spin values for Sagittarius A\* obtained with the outflow method"](https://academic.oup.com/mnras/article/527/1/428/7326786). *Monthly Notices of the Royal Astronomical Society*. **527** (1): 428–436\. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[2310\.12108](https://arxiv.org/abs/2310.12108). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1093/mnras/stad3228](https://doi.org/10.1093%2Fmnras%2Fstad3228). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0035-8711](https://search.worldcat.org/issn/0035-8711). 62. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-63)** Fragione, Giacomo; Loeb, Abraham (October 1, 2020). ["An Upper Limit on the Spin of SgrA\* Based on Stellar Orbits in Its Vicinity"](https://doi.org/10.3847%2F2041-8213%2Fabb9b4). *The Astrophysical Journal*. **901** (2): L32. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[2008\.11734](https://arxiv.org/abs/2008.11734). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2020ApJ...901L..32F](https://ui.adsabs.harvard.edu/abs/2020ApJ...901L..32F). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.3847/2041-8213/abb9b4](https://doi.org/10.3847%2F2041-8213%2Fabb9b4). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [2041-8213](https://search.worldcat.org/issn/2041-8213). 63. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-64)** BĂ©langer, G; Terrier, R; Jager, O C de; Goldwurm, A; Melia, F (December 1, 2006). ["Periodic Modulations in an X-ray Flare from Sagittarius A\*"](https://iopscience.iop.org/article/10.1088/1742-6596/54/1/066). *Journal of Physics: Conference Series*. **54**: 420–426\. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[astro-ph/0604337](https://arxiv.org/abs/astro-ph/0604337). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2006JPhCS..54..420B](https://ui.adsabs.harvard.edu/abs/2006JPhCS..54..420B). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1088/1742-6596/54/1/066](https://doi.org/10.1088%2F1742-6596%2F54%2F1%2F066). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [1742-6588](https://search.worldcat.org/issn/1742-6588). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [250670477](https://api.semanticscholar.org/CorpusID:250670477). 64. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-65)** Meyer, L.; Eckart, A.; Schödel, R.; Duschl, W. J.; MuĆŸić, K.; Dovčiak, M.; Karas, V. (December 2006). ["Near-infrared polarimetry setting constraints on the orbiting spot model for Sgr A\* flares"](http://www.aanda.org/10.1051/0004-6361:20065925). *Astronomy & Astrophysics*. **460** (1): 15–21\. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[astro-ph/0610104](https://arxiv.org/abs/astro-ph/0610104). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2006A\&A...460...15M](https://ui.adsabs.harvard.edu/abs/2006A&A...460...15M). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1051/0004-6361:20065925](https://doi.org/10.1051%2F0004-6361%3A20065925). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0004-6361](https://search.worldcat.org/issn/0004-6361). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [15370123](https://api.semanticscholar.org/CorpusID:15370123). 65. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-66)** Genzel, R.; Schödel, R.; Ott, T.; Eckart, A.; Alexander, T.; Lacombe, F.; Rouan, D.; Aschenbach, B. (November 2003). ["Near-infrared flares from accreting gas around the supermassive black hole at the Galactic Centre"](https://www.nature.com/articles/nature02065). *Nature*. **425** (6961): 934–937\. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[astro-ph/0310821](https://arxiv.org/abs/astro-ph/0310821). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2003Natur.425..934G](https://ui.adsabs.harvard.edu/abs/2003Natur.425..934G). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1038/nature02065](https://doi.org/10.1038%2Fnature02065). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0028-0836](https://search.worldcat.org/issn/0028-0836). [PMID](https://en.wikipedia.org/wiki/PMID_\(identifier\) "PMID (identifier)") [14586462](https://pubmed.ncbi.nlm.nih.gov/14586462). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [4325930](https://api.semanticscholar.org/CorpusID:4325930). 66. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-67)** Daly, Ruth A. (November 15, 2019). ["Black Hole Spin and Accretion Disk Magnetic Field Strength Estimates for More Than 750 Active Galactic Nuclei and Multiple Galactic Black Holes"](https://doi.org/10.3847%2F1538-4357%2Fab35e6). *The Astrophysical Journal*. **886** (1): 37. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[1905\.11319](https://arxiv.org/abs/1905.11319). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2019ApJ...886...37D](https://ui.adsabs.harvard.edu/abs/2019ApJ...886...37D). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.3847/1538-4357/ab35e6](https://doi.org/10.3847%2F1538-4357%2Fab35e6). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0004-637X](https://search.worldcat.org/issn/0004-637X). 67. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-:03_68-0)** Daly, Ruth A (October 20, 2022). ["Robust supermassive black hole spin mass-energy characteristics: a new method and results"](https://academic.oup.com/mnras/article/517/4/5144/6764739). *Monthly Notices of the Royal Astronomical Society*. **517** (4): 5144–5159\. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[2210\.07779](https://arxiv.org/abs/2210.07779). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1093/mnras/stac2976](https://doi.org/10.1093%2Fmnras%2Fstac2976). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0035-8711](https://search.worldcat.org/issn/0035-8711). 68. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Eisenhauer_69-0)** Eisenhauer, F.; et al. (July 20, 2005). "SINFONI in the Galactic Center: Young Stars and Infrared Flares in the Central Light-Month". *The Astrophysical Journal*. **628** (1): 246–259\. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[astro-ph/0502129](https://arxiv.org/abs/astro-ph/0502129). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2005ApJ...628..246E](https://ui.adsabs.harvard.edu/abs/2005ApJ...628..246E). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1086/430667](https://doi.org/10.1086%2F430667). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [122485461](https://api.semanticscholar.org/CorpusID:122485461). 69. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-70)** ["First Successful Test of Einstein's General Relativity Near Supermassive Black Hole – Culmination of 26 years of ESO observations of the heart of the Milky Way"](https://www.eso.org/public/news/eso1825/). *www.eso.org*. [Archived](https://web.archive.org/web/20190308114840/https://www.eso.org/public/news/eso1825/) from the original on March 8, 2019. Retrieved December 15, 2021. 70. ^ [***a***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-:0_71-0) [***b***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-:0_71-1) GRAVITY Collaboration; Abuter, R.; Amorim, A.; Anugu, N.; Bauböck, M.; Benisty, M.; Berger, J. P.; Blind, N.; Bonnet, H.; Brandner, W.; Buron, A. (July 2018). ["Detection of the gravitational redshift in the orbit of the star S2 near the Galactic centre massive black hole"](https://www.aanda.org/10.1051/0004-6361/201833718). *Astronomy & Astrophysics*. **615**: L15. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[1807\.09409](https://arxiv.org/abs/1807.09409). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2018A\&A...615L..15G](https://ui.adsabs.harvard.edu/abs/2018A&A...615L..15G). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1051/0004-6361/201833718](https://doi.org/10.1051%2F0004-6361%2F201833718). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0004-6361](https://search.worldcat.org/issn/0004-6361). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [118891445](https://api.semanticscholar.org/CorpusID:118891445). [Archived](https://web.archive.org/web/20200727101247/https://www.aanda.org/10.1051/0004-6361/201833718) from the original on July 27, 2020. Retrieved December 15, 2021. 71. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-72)** ["Watch stars move around the Milky Way's supermassive black hole in deepest images yet"](https://www.eso.org/public/news/eso2119/). *www.eso.org*. [Archived](https://web.archive.org/web/20211214172128/https://www.eso.org/public/news/eso2119/) from the original on December 14, 2021. Retrieved December 15, 2021. 72. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-73)** GRAVITY Collaboration; Stadler, J.; Drescher, A. (December 14, 2021). ["Deep images of the Galactic center with GRAVITY"](https://doi.org/10.1051%2F0004-6361%2F202142459). *Astronomy & Astrophysics*. **657**: A82. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[2112\.07477](https://arxiv.org/abs/2112.07477). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1051/0004-6361/202142459](https://doi.org/10.1051%2F0004-6361%2F202142459). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0004-6361](https://search.worldcat.org/issn/0004-6361). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [245131155](https://api.semanticscholar.org/CorpusID:245131155). 73. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-74)** GRAVITY Collaboration; Abuter, R.; Aimar, N.; Amorim, A.; Ball, J.; Bauböck, M.; Gillessen, S.; Widmann, F.; Heissel, G. (December 14, 2021). ["Mass distribution in the Galactic Center based on interferometric astrometry of multiple stellar orbits"](https://doi.org/10.1051%2F0004-6361%2F202142465). *Astronomy & Astrophysics*. **657**: L12. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[2112\.07478](https://arxiv.org/abs/2112.07478). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1051/0004-6361/202142465](https://doi.org/10.1051%2F0004-6361%2F202142465). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0004-6361](https://search.worldcat.org/issn/0004-6361). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [245131377](https://api.semanticscholar.org/CorpusID:245131377). 74. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-75)** Eckart, A.; Genzel, R.; Ott, T.; Schödel, R. (April 11, 2002). ["Stellar orbits near Sagittarius A\*"](https://doi.org/10.1046%2Fj.1365-8711.2002.05237.x). *Monthly Notices of the Royal Astronomical Society*. **331** (4): 917–934\. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[astro-ph/0201031](https://arxiv.org/abs/astro-ph/0201031). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2002MNRAS.331..917E](https://ui.adsabs.harvard.edu/abs/2002MNRAS.331..917E). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1046/j.1365-8711.2002.05237.x](https://doi.org/10.1046%2Fj.1365-8711.2002.05237.x). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0035-8711](https://search.worldcat.org/issn/0035-8711). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [11167996](https://api.semanticscholar.org/CorpusID:11167996). 75. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-apj_76-0)** Peissker, Florian; Eckart, Andreas; Parsa, Marzieh (January 2020). ["S62 on a 9.9 year orbit around SgrA\*"](https://doi.org/10.3847%2F1538-4357%2Fab5afd). *[The Astrophysical Journal](https://en.wikipedia.org/wiki/The_Astrophysical_Journal "The Astrophysical Journal")*. **889** (1): 61. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[2002\.02341](https://arxiv.org/abs/2002.02341). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2020ApJ...889...61P](https://ui.adsabs.harvard.edu/abs/2020ApJ...889...61P). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.3847/1538-4357/ab5afd](https://doi.org/10.3847%2F1538-4357%2Fab5afd). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [211043784](https://api.semanticscholar.org/CorpusID:211043784). 76. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-p994_77-0)** GRAVITY Collaboration (2021). ["Detection of faint stars near Sagittarius A\* with GRAVITY"](https://www.aanda.org/articles/aa/pdf/2021/01/aa39544-20.pdf) (PDF). *Astronomy & Astrophysics*. **645**: A127. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[2011\.03058](https://arxiv.org/abs/2011.03058). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2021A\&A...645A.127G](https://ui.adsabs.harvard.edu/abs/2021A&A...645A.127G). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1051/0004-6361/202039544](https://doi.org/10.1051%2F0004-6361%2F202039544). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0004-6361](https://search.worldcat.org/issn/0004-6361). Retrieved December 29, 2024. 77. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-78)** Peißker, Florian; Eckart, Andreas; Zajaček, Michal; Basel, Ali; Parsa, Marzieh (August 2020). ["S62 and S4711: Indications of a Population of Faint Fast-moving Stars inside the S2 Orbit—S4711 on a 7.6 yr Orbit around Sgr A\*"](https://doi.org/10.3847%2F1538-4357%2Fab9c1c). *[The Astrophysical Journal](https://en.wikipedia.org/wiki/The_Astrophysical_Journal "The Astrophysical Journal")*. **889** (50): 5. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[2008\.04764](https://arxiv.org/abs/2008.04764). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2020ApJ...899...50P](https://ui.adsabs.harvard.edu/abs/2020ApJ...899...50P). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.3847/1538-4357/ab9c1c](https://doi.org/10.3847%2F1538-4357%2Fab9c1c). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [221095771](https://api.semanticscholar.org/CorpusID:221095771). 78. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-naess_79-0)** NĂŠss, S. (October 4, 2019). ["Galactic center S-star orbital parameters"](http://folk.uio.no/sigurdkn/s_stars). 79. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Matson_80-0)** Matson, John (October 22, 2012). ["Gas Guzzler: Cloud Could Soon Meet Its Demise in Milky Way's Black Hole"](https://web.archive.org/web/20130619093354/https://www.llnl.gov/news/newsreleases/2012/Oct/NR-12-10-07.html). Scientific American. Archived from [the original](https://www.llnl.gov/news/newsreleases/2012/Oct/NR-12-10-07.html) on June 19, 2013. Retrieved October 30, 2012. 80. ^ [***a***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Gillessen_2012_51%E2%80%9354_81-0) [***b***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Gillessen_2012_51%E2%80%9354_81-1) Gillessen, S.; Genzel, R.; Fritz, T. K.; Quataert, E.; Alig, C.; Burkert, A.; Cuadra, J.; Eisenhauer, F.; Pfuhl, O.; Dodds-Eden, K.; Gammie, C. F.; Ott, T. (January 2012). "A gas cloud on its way towards the supermassive black hole at the Galactic Centre". *Nature*. **481** (7379): 51–54\. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[1112\.3264](https://arxiv.org/abs/1112.3264). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2012Natur.481...51G](https://ui.adsabs.harvard.edu/abs/2012Natur.481...51G). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1038/nature10652](https://doi.org/10.1038%2Fnature10652). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0028-0836](https://search.worldcat.org/issn/0028-0836). [PMID](https://en.wikipedia.org/wiki/PMID_\(identifier\) "PMID (identifier)") [22170607](https://pubmed.ncbi.nlm.nih.gov/22170607). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [4410915](https://api.semanticscholar.org/CorpusID:4410915). 81. ^ [***a***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Witzel2014_82-0) [***b***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Witzel2014_82-1) [***c***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Witzel2014_82-2) Witzel, G.; Ghez, A. M.; Morris, M. R.; Sitarski, B. N.; Boehle, A.; Naoz, S.; Campbell, R.; Becklin, E. E.; G. Canalizo; Chappell, S.; Do, T.; Lu, J. R.; Matthews, K.; Meyer, L.; Stockton, A.; Wizinowich, P.; Yelda, S. (January 1, 2014). "Detection of Galactic Center Source G2 at 3.8 ÎŒm during Periapse Passage". *Astrophysical Journal Letters*. **796** (1): L8. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[1410\.1884](https://arxiv.org/abs/1410.1884). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2014ApJ...796L...8W](https://ui.adsabs.harvard.edu/abs/2014ApJ...796L...8W). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1088/2041-8205/796/1/L8](https://doi.org/10.1088%2F2041-8205%2F796%2F1%2FL8). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [36797915](https://api.semanticscholar.org/CorpusID:36797915). 82. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Bartos_83-0)** Bartos, Imre; Haiman, ZoltĂĄn; Kocsis, Bence; MĂĄrka, Szabolcs (May 2013). "Gas Cloud G2 Can Illuminate the Black Hole Population Near the Galactic Center". *Physical Review Letters*. **110** (22): 221102 (5 pages). [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[1302\.3220](https://arxiv.org/abs/1302.3220). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2013PhRvL.110v1102B](https://ui.adsabs.harvard.edu/abs/2013PhRvL.110v1102B). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1103/PhysRevLett.110.221102](https://doi.org/10.1103%2FPhysRevLett.110.221102). [PMID](https://en.wikipedia.org/wiki/PMID_\(identifier\) "PMID (identifier)") [23767710](https://pubmed.ncbi.nlm.nih.gov/23767710). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [12284209](https://api.semanticscholar.org/CorpusID:12284209). 83. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Geometry_84-0)** de la Fuente Marcos, R.; de la Fuente Marcos, C. (August 2013). ["Colliding with G2 near the Galactic Centre: a geometrical approach"](https://doi.org/10.1093%2Fmnrasl%2Fslt085). *[Monthly Notices of the Royal Astronomical Society: Letters](https://en.wikipedia.org/wiki/Monthly_Notices_of_the_Royal_Astronomical_Society:_Letters "Monthly Notices of the Royal Astronomical Society: Letters")*. **435** (1): L19–L23. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[1306\.4921](https://arxiv.org/abs/1306.4921). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2013MNRAS.435L..19D](https://ui.adsabs.harvard.edu/abs/2013MNRAS.435L..19D). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1093/mnrasl/slt085](https://doi.org/10.1093%2Fmnrasl%2Fslt085). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [119287777](https://api.semanticscholar.org/CorpusID:119287777). 84. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-85)** Morris, Mark (January 4, 2012). ["Astrophysics: The Final Plunge"](https://doi.org/10.1038%2Fnature10767). *Nature*. **481** (7379): 32–33\. [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2012Natur.481...32M](https://ui.adsabs.harvard.edu/abs/2012Natur.481...32M). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1038/nature10767](https://doi.org/10.1038%2Fnature10767). [PMID](https://en.wikipedia.org/wiki/PMID_\(identifier\) "PMID (identifier)") [22170611](https://pubmed.ncbi.nlm.nih.gov/22170611). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [664513](https://api.semanticscholar.org/CorpusID:664513). 85. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-86)** Gillessen. ["Wiki Page of Proposed Observations of G2 Passage"](https://wiki.mpe.mpg.de/gascloud/ProposalList). [Archived](https://web.archive.org/web/20140201203116/https://wiki.mpe.mpg.de/gascloud/ProposalList) from the original on February 1, 2014. Retrieved October 30, 2012. 86. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-87)** ["A Black Hole's Dinner is Fast Approaching"](http://www.eso.org/public/news/eso1151/). ESO. December 14, 2011. [Archived](https://web.archive.org/web/20120213173904/http://www.eso.org/public/news/eso1151/) from the original on February 13, 2012. Retrieved February 27, 2015. 87. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-88)** H Hirschfeld, Robert (October 22, 2012). ["Milky Way's black hole getting ready for snack"](https://web.archive.org/web/20130619093354/https://www.llnl.gov/news/newsreleases/2012/Oct/NR-12-10-07.html). [Lawrence Livermore National Laboratory](https://en.wikipedia.org/wiki/Lawrence_Livermore_National_Laboratory "Lawrence Livermore National Laboratory"). Archived from [the original](https://www.llnl.gov/news/newsreleases/2012/Oct/NR-12-10-07.html) on June 19, 2013. Retrieved February 27, 2015. 88. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-89)** Taylor Tillman, Nola (April 28, 2014). ["Doomed Space Cloud Nears Milky Way's Black Hole as Scientists Watch"](https://www.space.com/25665-doomed-space-cloud-giant-black-hole.html). *[Space.com](https://en.wikipedia.org/wiki/Space.com "Space.com")*. Retrieved September 15, 2024. "Cosmic encounter that might reveal new secrets on how such supermassive black holes evolve; We get to watch it unfolding in a human lifetime, which is very unusual and very exciting" 89. ^ [***a***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-nature140721_90-0) [***b***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-nature140721_90-1) Cowen, Ron (2014). ["Why galactic black hole fireworks were a flop : Nature News & Comment"](http://www.nature.com/news/why-galactic-black-hole-fireworks-were-a-flop-1.15591). *Nature*. [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1038/nature.2014.15591](https://doi.org/10.1038%2Fnature.2014.15591). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [124346286](https://api.semanticscholar.org/CorpusID:124346286). [Archived](https://web.archive.org/web/20150219013446/http://www.nature.com/news/why-galactic-black-hole-fireworks-were-a-flop-1.15591) from the original on February 19, 2015. Retrieved February 27, 2015. 90. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-91)** Pfuhl, Oliver; Gillessen, Stefan; Eisenhauer, Frank; Genzel, Reinhard; Plewa, Philipp M.; Thomas Ott; Ballone, Alessandro; Schartmann, Marc; Burkert, Andreas (2015). "The Galactic Center Cloud G2 and its Gas Streamer". *The Astrophysical Journal*. **798** (2): 111. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[1407\.4354](https://arxiv.org/abs/1407.4354). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2015ApJ...798..111P](https://ui.adsabs.harvard.edu/abs/2015ApJ...798..111P). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1088/0004-637x/798/2/111](https://doi.org/10.1088%2F0004-637x%2F798%2F2%2F111). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0004-637X](https://search.worldcat.org/issn/0004-637X). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [118440030](https://api.semanticscholar.org/CorpusID:118440030). 91. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-92)** ["How G2 survived the black hole at our Milky Way's heart - EarthSky.org"](http://earthsky.org/space/how-g2-survived-the-black-hole-at-our-milky-ways-heart). November 4, 2014. [Archived](https://web.archive.org/web/20160205014740/http://earthsky.org/space/how-g2-survived-the-black-hole-at-our-milky-ways-heart) from the original on February 5, 2016. Retrieved February 14, 2016. 92. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-93)** ["Simulation of gas cloud after close approach to the black hole at the centre of the Milky Way"](http://www.eso.org/public/images/eso1151a/). ESO. [Archived](https://web.archive.org/web/20150307130323/http://www.eso.org/public/images/eso1151a/) from the original on March 7, 2015. Retrieved February 27, 2015. ## Further reading \[[edit](https://en.wikipedia.org/w/index.php?title=Sagittarius_A*&action=edit&section=9 "Edit section: Further reading")\] - Backer, D. C. & Sramek, R. A. (October 20, 1999). "Proper Motion of the Compact, Nonthermal Radio Source in the Galactic Center, Sagittarius A\*". *[The Astrophysical Journal](https://en.wikipedia.org/wiki/The_Astrophysical_Journal "The Astrophysical Journal")*. **524** (2): 805–815\. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[astro-ph/9906048](https://arxiv.org/abs/astro-ph/9906048). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[1999ApJ...524..805B](https://ui.adsabs.harvard.edu/abs/1999ApJ...524..805B). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1086/307857](https://doi.org/10.1086%2F307857). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0004-637X](https://search.worldcat.org/issn/0004-637X). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [18858138](https://api.semanticscholar.org/CorpusID:18858138). - Gillessen, Stefan; et al. (February 23, 2009). "Monitoring stellar orbits around the Massive Black Hole in the Galactic Center". *The Astrophysical Journal*. **692** (2): 1075–1109\. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[0810\.4674](https://arxiv.org/abs/0810.4674). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2009ApJ...692.1075G](https://ui.adsabs.harvard.edu/abs/2009ApJ...692.1075G). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1088/0004-637X/692/2/1075](https://doi.org/10.1088%2F0004-637X%2F692%2F2%2F1075). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [1431308](https://api.semanticscholar.org/CorpusID:1431308). - Melia, Fulvio (2007). *The galactic supermassive black hole*. Princeton: Princeton Univ. [ISBN](https://en.wikipedia.org/wiki/ISBN_\(identifier\) "ISBN (identifier)") [978-0-691-13129-0](https://en.wikipedia.org/wiki/Special:BookSources/978-0-691-13129-0 "Special:BookSources/978-0-691-13129-0") . - O'Neill, Ian (December 10, 2008). ["Beyond Any Reasonable Doubt: A Supermassive Black Hole Lives in Centre of Our Galaxy"](https://www.universetoday.com/22104/beyond-any-reasonable-doubt-a-supermassive-black-hole-lives-in-centre-of-our-galaxy/). [Universe Today](https://en.wikipedia.org/wiki/Universe_Today "Universe Today"). - Osterbrock, Donald E. & Ferland, Gary J. (2006). [*Astrophysics of gaseous nebulae and active galactic nuclei*](https://archive.org/details/astrophysicsofga0000oste) (2nd ed.). Mill Valley, California: University Science Books. [ISBN](https://en.wikipedia.org/wiki/ISBN_\(identifier\) "ISBN (identifier)") [978-1-891389-34-4](https://en.wikipedia.org/wiki/Special:BookSources/978-1-891389-34-4 "Special:BookSources/978-1-891389-34-4") . - Reid, M. J.; Brunthaler, A. (December 2004). "The Proper Motion of Sagittarius A\*. II. The Mass of Sagittarius A\*". *[The Astrophysical Journal](https://en.wikipedia.org/wiki/The_Astrophysical_Journal "The Astrophysical Journal")*. **616** (2): 872–884\. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[astro-ph/0408107](https://arxiv.org/abs/astro-ph/0408107). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2004ApJ...616..872R](https://ui.adsabs.harvard.edu/abs/2004ApJ...616..872R). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1086/424960](https://doi.org/10.1086%2F424960). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0004-637X](https://search.worldcat.org/issn/0004-637X). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [16568545](https://api.semanticscholar.org/CorpusID:16568545). - Schödel, R.; et al. (October 2002). "A star in a 15.2-year orbit around the supermassive black hole at the centre of the Milky Way". *[Nature](https://en.wikipedia.org/wiki/Nature_\(journal\) "Nature (journal)")*. **419** (6908): 694–696\. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[astro-ph/0210426](https://arxiv.org/abs/astro-ph/0210426). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2002Natur.419..694S](https://ui.adsabs.harvard.edu/abs/2002Natur.419..694S). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1038/nature01121](https://doi.org/10.1038%2Fnature01121). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0028-0836](https://search.worldcat.org/issn/0028-0836). [PMID](https://en.wikipedia.org/wiki/PMID_\(identifier\) "PMID (identifier)") [12384690](https://pubmed.ncbi.nlm.nih.gov/12384690). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [4302128](https://api.semanticscholar.org/CorpusID:4302128). - Schödel, R.; [Merritt, D.](https://en.wikipedia.org/wiki/David_Merritt "David Merritt"); Eckart, A. (July 2009). "The nuclear star cluster of the Milky Way: proper motions and mass". *[Astronomy & Astrophysics](https://en.wikipedia.org/wiki/Astronomy_%26_Astrophysics "Astronomy & Astrophysics")*. **502** (1): 91–111\. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[0902\.3892](https://arxiv.org/abs/0902.3892). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2009A\&A...502...91S](https://ui.adsabs.harvard.edu/abs/2009A&A...502...91S). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1051/0004-6361/200810922](https://doi.org/10.1051%2F0004-6361%2F200810922). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0004-6361](https://search.worldcat.org/issn/0004-6361). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [219559](https://api.semanticscholar.org/CorpusID:219559). - Melia, Fulvio (2003). [*The black hole at the center of our galaxy*](https://archive.org/details/blackholeatcente0000meli). Princeton: Princeton University Press. [ISBN](https://en.wikipedia.org/wiki/ISBN_\(identifier\) "ISBN (identifier)") [978-0-691-09505-9](https://en.wikipedia.org/wiki/Special:BookSources/978-0-691-09505-9 "Special:BookSources/978-0-691-09505-9") . - Doeleman, Sheperd S.; et al. (September 2008). "Event-horizon-scale structure in the supermassive black hole candidate at the Galactic Centre". *Nature*. **455** (7209): 78–80\. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[0809\.2442](https://arxiv.org/abs/0809.2442). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2008Natur.455...78D](https://ui.adsabs.harvard.edu/abs/2008Natur.455...78D). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1038/nature07245](https://doi.org/10.1038%2Fnature07245). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0028-0836](https://search.worldcat.org/issn/0028-0836). [PMID](https://en.wikipedia.org/wiki/PMID_\(identifier\) "PMID (identifier)") [18769434](https://pubmed.ncbi.nlm.nih.gov/18769434). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [4424735](https://api.semanticscholar.org/CorpusID:4424735). - Eckart, Andreas; Schödel, Rainer; Straubmeier, Christian Michael; Straubmeier, Christian (2005). *The black hole at the center of the Milky Way*. London: Imperial College Press. [ISBN](https://en.wikipedia.org/wiki/ISBN_\(identifier\) "ISBN (identifier)") [978-1-86094-567-0](https://en.wikipedia.org/wiki/Special:BookSources/978-1-86094-567-0 "Special:BookSources/978-1-86094-567-0") . - Eisenhauer, F.; Schdel, R.; Genzel, R.; Ott, T.; Tecza, M.; Abuter, R.; Eckart, A.; Alexander, T.; et al. (November 10, 2003). "A Geometric Determination of the Distance to the Galactic Center". *[The Astrophysical Journal](https://en.wikipedia.org/wiki/The_Astrophysical_Journal "The Astrophysical Journal")*. **597** (2): L121–L124. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[astro-ph/0306220](https://arxiv.org/abs/astro-ph/0306220). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2003ApJ...597L.121E](https://ui.adsabs.harvard.edu/abs/2003ApJ...597L.121E). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1086/380188](https://doi.org/10.1086%2F380188). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0004-637X](https://search.worldcat.org/issn/0004-637X). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [16425333](https://api.semanticscholar.org/CorpusID:16425333). - [The Event Horizon Telescope Collaboration](https://en.wikipedia.org/wiki/Event_Horizon_Telescope "Event Horizon Telescope") (April 10, 2019). ["First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole"](https://doi.org/10.3847%2F2041-8213%2Fab0ec7). *[The Astrophysical Journal Letters](https://en.wikipedia.org/wiki/The_Astrophysical_Journal_Letters "The Astrophysical Journal Letters")*. **875** (1): L1. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[1906\.11238](https://arxiv.org/abs/1906.11238). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2019ApJ...875L...1E](https://ui.adsabs.harvard.edu/abs/2019ApJ...875L...1E). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.3847/2041-8213/ab0ec7](https://doi.org/10.3847%2F2041-8213%2Fab0ec7). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [145906806](https://api.semanticscholar.org/CorpusID:145906806). - Ghez, A. M.; et al. (April 1, 2003). "The First Measurement of Spectral Lines in a Short-Period Star Bound to the Galaxy's Central Black Hole: A Paradox of Youth". *[The Astrophysical Journal](https://en.wikipedia.org/wiki/The_Astrophysical_Journal "The Astrophysical Journal")*. **586** (2): L127–L131. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[astro-ph/0302299](https://arxiv.org/abs/astro-ph/0302299). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2003ApJ...586L.127G](https://ui.adsabs.harvard.edu/abs/2003ApJ...586L.127G). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1086/374804](https://doi.org/10.1086%2F374804). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [11388341](https://api.semanticscholar.org/CorpusID:11388341). - Ghez, A. M.; et al. (December 20, 2008). "Measuring Distance and Properties of the Milky Way's Central Supermassive Black Hole with Stellar Orbits". *[The Astrophysical Journal](https://en.wikipedia.org/wiki/The_Astrophysical_Journal "The Astrophysical Journal")*. **689** (2): 1044–1062\. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[0808\.2870](https://arxiv.org/abs/0808.2870). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2008ApJ...689.1044G](https://ui.adsabs.harvard.edu/abs/2008ApJ...689.1044G). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1086/592738](https://doi.org/10.1086%2F592738). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0004-637X](https://search.worldcat.org/issn/0004-637X). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [18335611](https://api.semanticscholar.org/CorpusID:18335611). - Reynolds, Christopher S. (September 2008). "Bringing black holes into focus". *[Nature](https://en.wikipedia.org/wiki/Nature_\(journal\) "Nature (journal)")*. **455** (7209): 39–40\. [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2008Natur.455...39R](https://ui.adsabs.harvard.edu/abs/2008Natur.455...39R). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1038/455039a](https://doi.org/10.1038%2F455039a). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0028-0836](https://search.worldcat.org/issn/0028-0836). [PMID](https://en.wikipedia.org/wiki/PMID_\(identifier\) "PMID (identifier)") [18769426](https://pubmed.ncbi.nlm.nih.gov/18769426). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [205040663](https://api.semanticscholar.org/CorpusID:205040663). - Wheeler, J. Craig (2007). *Cosmic catastrophes: exploding stars, black holes, and mapping the universe* (2nd ed.). Cambridge; New York: [Cambridge University Press](https://en.wikipedia.org/wiki/Cambridge_University_Press "Cambridge University Press"). [ISBN](https://en.wikipedia.org/wiki/ISBN_\(identifier\) "ISBN (identifier)") [978-0-521-85714-7](https://en.wikipedia.org/wiki/Special:BookSources/978-0-521-85714-7 "Special:BookSources/978-0-521-85714-7") . [OCLC](https://en.wikipedia.org/wiki/OCLC_\(identifier\) "OCLC (identifier)") [73954922](https://search.worldcat.org/oclc/73954922). - Banner, Tanja (March 2, 2023). ["Eigentlich dĂŒrfte er nicht existieren: Babystern nah an schwarzem Loch entdeckt"](https://www.fr.de/wissen/schwarzes-loch-zentrum-milchstrasse-sagittarius-a-junger-stern-unmoeglich-existenz-forschung-studie-news-92116242.html). *[Frankfurter Rundschau](https://en.wikipedia.org/wiki/Frankfurter_Rundschau "Frankfurter Rundschau")* (in German). Retrieved March 2, 2023. - Peißker, F.; Zajaček, M.; Melamed, M.; Ali, B.; Singhal, M.; Dassel, T.; Eckart, A.; Karas, V. (June 2024). "Candidate young stellar objects in the S-cluster: Kinematic analysis of a subpopulation of the low-mass G objects close to Sgr A\*". *[Astronomy & Astrophysics](https://en.wikipedia.org/wiki/Astronomy_%26_Astrophysics "Astronomy & Astrophysics")*. **686**: A235. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[2406\.09916](https://arxiv.org/abs/2406.09916). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2024A\&A...686A.235P](https://ui.adsabs.harvard.edu/abs/2024A&A...686A.235P). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1051/0004-6361/202449729](https://doi.org/10.1051%2F0004-6361%2F202449729). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0004-6361](https://search.worldcat.org/issn/0004-6361). - Rayne, Elizabeth (July 4, 2024). ["Swarm of dusty young stars found around our galaxy's central black hole"](https://arstechnica.com/science/2024/07/swarm-of-dusty-young-stars-found-around-our-galaxys-central-black-hole/). *Ars Technica*. Retrieved July 5, 2024. ## External links \[[edit](https://en.wikipedia.org/w/index.php?title=Sagittarius_A*&action=edit&section=10 "Edit section: External links")\] - [Is there a Supermassive Black Hole at the Center of the Milky Way?](https://arxiv.org/abs/0808.2624) ([arXiv](https://en.wikipedia.org/wiki/ArXiv "ArXiv") preprint) - [2004 paper deducing mass of central black hole from orbits of 7 stars](https://arxiv.org/abs/astro-ph/0306130) ([arXiv](https://en.wikipedia.org/wiki/ArXiv "ArXiv") preprint) - [ESO video clip of orbiting star](http://www.eso.org/public/archives/videos/old_video/eso0226a.mpg) (533 KB MPEG Video) - [The Proper Motion of Sgr A\* and the Mass of Sgr A\*](https://arxiv.org/abs/astro-ph/0408107) (PDF) - [NRAO article](http://www.nrao.edu/pr/1998/bhole/) regarding VLBI radio imaging of Sgr A\* - [Peering into a Black Hole](https://www.nytimes.com/video/science/100000003725182/peering-into-a-black-hole.html), 2015 *New York Times* video - [Image of supermassive black hole Sagittarius A\* (2022)](https://pweb.cfa.harvard.edu/news/9741/imagelist), Harvard Center for Astrophysics - [Video (65:30) – EHT conference presenting first image of Sgr A\*](https://www.youtube.com/watch?v=4Ws0iPDSqI4) on [YouTube](https://en.wikipedia.org/wiki/YouTube_video_\(identifier\) "YouTube video (identifier)") ([NSF](https://en.wikipedia.org/wiki/National_Science_Foundation "National Science Foundation"); 12 May 2022) | [v](https://en.wikipedia.org/wiki/Template:Black_holes "Template:Black holes") [t](https://en.wikipedia.org/wiki/Template_talk:Black_holes "Template talk:Black holes") [e](https://en.wikipedia.org/wiki/Special:EditPage/Template:Black_holes "Special:EditPage/Template:Black holes")[Black holes](https://en.wikipedia.org/wiki/Black_hole "Black hole") | | |---|---| | [Outline](https://en.wikipedia.org/wiki/Outline_of_black_holes "Outline of black holes") | | | Types | [BTZ black hole](https://en.wikipedia.org/wiki/BTZ_black_hole "BTZ black hole") [Schwarzschild](https://en.wikipedia.org/wiki/Schwarzschild_metric "Schwarzschild metric") [Rotating](https://en.wikipedia.org/wiki/Rotating_black_hole "Rotating black hole") [Charged](https://en.wikipedia.org/wiki/Charged_black_hole "Charged black hole") [Virtual](https://en.wikipedia.org/wiki/Virtual_black_hole "Virtual black hole") [Kugelblitz](https://en.wikipedia.org/wiki/Kugelblitz_\(astrophysics\) "Kugelblitz (astrophysics)") [Supermassive](https://en.wikipedia.org/wiki/Supermassive_black_hole "Supermassive black hole") [Primordial](https://en.wikipedia.org/wiki/Primordial_black_hole "Primordial black hole") [Direct collapse](https://en.wikipedia.org/wiki/Direct_collapse_black_hole "Direct collapse black hole") [Rogue](https://en.wikipedia.org/wiki/Rogue_black_hole "Rogue black hole") [Malament–Hogarth spacetime](https://en.wikipedia.org/wiki/Malament%E2%80%93Hogarth_spacetime "Malament–Hogarth spacetime") | | Size | [Micro](https://en.wikipedia.org/wiki/Micro_black_hole "Micro black hole") [Extremal](https://en.wikipedia.org/wiki/Extremal_black_hole "Extremal black hole") [Electron](https://en.wikipedia.org/wiki/Black_hole_electron "Black hole electron") [Stellar](https://en.wikipedia.org/wiki/Stellar_black_hole "Stellar black hole") [Microquasar](https://en.wikipedia.org/wiki/Microquasar "Microquasar") [Intermediate-mass](https://en.wikipedia.org/wiki/Intermediate-mass_black_hole "Intermediate-mass black hole") [Supermassive](https://en.wikipedia.org/wiki/Supermassive_black_hole "Supermassive black hole") [Active galactic nucleus](https://en.wikipedia.org/wiki/Active_galactic_nucleus "Active galactic nucleus") [Quasar](https://en.wikipedia.org/wiki/Quasar "Quasar") [LQG](https://en.wikipedia.org/wiki/Large_quasar_group "Large quasar group") [Blazar](https://en.wikipedia.org/wiki/Blazar "Blazar") [BL Lac](https://en.wikipedia.org/wiki/BL_Lacertae_object "BL Lacertae object") [FSRQ](https://en.wikipedia.org/wiki/Flat-spectrum_radio_quasar "Flat-spectrum radio quasar") | | Formation | [Stellar evolution](https://en.wikipedia.org/wiki/Stellar_evolution "Stellar evolution") [Gravitational collapse](https://en.wikipedia.org/wiki/Gravitational_collapse "Gravitational collapse") [Neutron star](https://en.wikipedia.org/wiki/Neutron_star "Neutron star") [Related links](https://en.wikipedia.org/wiki/Template:Neutron_star "Template:Neutron star") [Tolman–Oppenheimer–Volkoff limit](https://en.wikipedia.org/wiki/Tolman%E2%80%93Oppenheimer%E2%80%93Volkoff_limit "Tolman–Oppenheimer–Volkoff limit") [Oppenheimer–Snyder model](https://en.wikipedia.org/wiki/Oppenheimer%E2%80%93Snyder_model "Oppenheimer–Snyder model") [White dwarf](https://en.wikipedia.org/wiki/White_dwarf "White dwarf") [Related links](https://en.wikipedia.org/wiki/Template:White_dwarf "Template:White dwarf") [Supernova](https://en.wikipedia.org/wiki/Supernova "Supernova") [Micronova](https://en.wikipedia.org/wiki/Micronova "Micronova") [Hypernova](https://en.wikipedia.org/wiki/Superluminous_supernova "Superluminous supernova") [Related links](https://en.wikipedia.org/wiki/Template:Supernovae "Template:Supernovae") [Gamma-ray burst](https://en.wikipedia.org/wiki/Gamma-ray_burst "Gamma-ray burst") [Binary black hole](https://en.wikipedia.org/wiki/Binary_black_hole "Binary black hole") [Quark star](https://en.wikipedia.org/wiki/Quark_star "Quark star") [Supermassive star](https://en.wikipedia.org/wiki/Supermassive_star "Supermassive star") [Quasi-star](https://en.wikipedia.org/wiki/Quasi-star "Quasi-star") [Supermassive dark star](https://en.wikipedia.org/wiki/Dark_star_\(dark_matter\) "Dark star (dark matter)") [X-ray binary](https://en.wikipedia.org/wiki/X-ray_binary "X-ray binary") | | Properties | [Astrophysical jet](https://en.wikipedia.org/wiki/Astrophysical_jet "Astrophysical jet") [Gravitational singularity](https://en.wikipedia.org/wiki/Gravitational_singularity "Gravitational singularity") [Ring singularity](https://en.wikipedia.org/wiki/Ring_singularity "Ring singularity") [BKL singularity](https://en.wikipedia.org/wiki/BKL_singularity "BKL singularity") [Shock singularity](https://en.wikipedia.org/wiki/Shock_singularity "Shock singularity") [Theorems](https://en.wikipedia.org/wiki/Penrose%E2%80%93Hawking_singularity_theorems "Penrose–Hawking singularity theorems") [Event horizon](https://en.wikipedia.org/wiki/Event_horizon "Event horizon") [Photon sphere](https://en.wikipedia.org/wiki/Photon_sphere "Photon sphere") [Innermost stable circular orbit](https://en.wikipedia.org/wiki/Innermost_stable_circular_orbit "Innermost stable circular orbit") [Ergosphere](https://en.wikipedia.org/wiki/Ergosphere "Ergosphere") [Penrose process](https://en.wikipedia.org/wiki/Penrose_process "Penrose process") [Blandford–Znajek process](https://en.wikipedia.org/wiki/Blandford%E2%80%93Znajek_process "Blandford–Znajek process") [Accretion disk](https://en.wikipedia.org/wiki/Accretion_disk "Accretion disk") [Hawking radiation](https://en.wikipedia.org/wiki/Hawking_radiation "Hawking radiation") [Gravitational lens](https://en.wikipedia.org/wiki/Gravitational_lens "Gravitational lens") [Microlens](https://en.wikipedia.org/wiki/Gravitational_microlensing "Gravitational microlensing") [Cauchy horizon](https://en.wikipedia.org/wiki/Cauchy_horizon "Cauchy horizon") [Mass inflation](https://en.wikipedia.org/wiki/Mass_inflation "Mass inflation") [Bondi accretion](https://en.wikipedia.org/wiki/Bondi_accretion "Bondi accretion") [M–sigma relation](https://en.wikipedia.org/wiki/M%E2%80%93sigma_relation "M–sigma relation") [Quasi-periodic oscillation](https://en.wikipedia.org/wiki/Quasi-periodic_oscillation "Quasi-periodic oscillation") [Thermodynamics](https://en.wikipedia.org/wiki/Black_hole_thermodynamics "Black hole thermodynamics") [Bekenstein bound](https://en.wikipedia.org/wiki/Bekenstein_bound "Bekenstein bound") [Bousso's holographic bound](https://en.wikipedia.org/wiki/Bousso%27s_holographic_bound "Bousso's holographic bound") [Immirzi parameter](https://en.wikipedia.org/wiki/Immirzi_parameter "Immirzi parameter") [Schwarzschild radius](https://en.wikipedia.org/wiki/Schwarzschild_radius "Schwarzschild radius") [Spaghettification](https://en.wikipedia.org/wiki/Spaghettification "Spaghettification") | | Issues | [Information paradox](https://en.wikipedia.org/wiki/Black_hole_information_paradox "Black hole information paradox") [Complementarity](https://en.wikipedia.org/wiki/Black_hole_complementarity "Black hole complementarity") [Soft hair](https://en.wikipedia.org/wiki/Soft_hair_\(black_holes\) "Soft hair (black holes)") [Cosmic censorship](https://en.wikipedia.org/wiki/Cosmic_censorship_hypothesis "Cosmic censorship hypothesis") [ER = EPR](https://en.wikipedia.org/wiki/ER_%3D_EPR "ER = EPR") [Final parsec problem](https://en.wikipedia.org/wiki/Binary_black_hole#Final_parsec_problem "Binary black hole") [Firewall (physics)](https://en.wikipedia.org/wiki/Firewall_\(physics\) "Firewall (physics)") [Holographic principle](https://en.wikipedia.org/wiki/Holographic_principle "Holographic principle") [No-hair theorem](https://en.wikipedia.org/wiki/No-hair_theorem "No-hair theorem") | | Metrics | [Schwarzschild](https://en.wikipedia.org/wiki/Schwarzschild_metric "Schwarzschild metric") ([Derivation](https://en.wikipedia.org/wiki/Derivation_of_the_Schwarzschild_solution "Derivation of the Schwarzschild solution")) [Kerr](https://en.wikipedia.org/wiki/Kerr_metric "Kerr metric") [Reissner–Nordström](https://en.wikipedia.org/wiki/Reissner%E2%80%93Nordstr%C3%B6m_metric "Reissner–Nordström metric") [Kerr–Newman](https://en.wikipedia.org/wiki/Kerr%E2%80%93Newman_metric "Kerr–Newman metric") [Hayward](https://en.wikipedia.org/wiki/Hayward_metric "Hayward metric") | | Alternatives | [Nonsingular black hole models](https://en.wikipedia.org/wiki/Nonsingular_black_hole_models "Nonsingular black hole models") [Black star](https://en.wikipedia.org/wiki/Black_star_\(semiclassical_gravity\) "Black star (semiclassical gravity)") [Dark star](https://en.wikipedia.org/wiki/Dark_star_\(Newtonian_mechanics\) "Dark star (Newtonian mechanics)") [Dark-energy star](https://en.wikipedia.org/wiki/Dark-energy_star "Dark-energy star") [Gravastar](https://en.wikipedia.org/wiki/Gravastar "Gravastar") [Magnetospheric eternally collapsing object](https://en.wikipedia.org/wiki/Magnetospheric_eternally_collapsing_object "Magnetospheric eternally collapsing object") [Planck star](https://en.wikipedia.org/wiki/Planck_star "Planck star") [Q star](https://en.wikipedia.org/wiki/Q_star "Q star") [Fuzzball](https://en.wikipedia.org/wiki/Fuzzball_\(string_theory\) "Fuzzball (string theory)") [Geon](https://en.wikipedia.org/wiki/Geon_\(physics\) "Geon (physics)") | | Analogs | [Optical black hole](https://en.wikipedia.org/wiki/Optical_black_hole "Optical black hole") [Sonic black hole](https://en.wikipedia.org/wiki/Sonic_black_hole "Sonic black hole") | | [Lists](https://en.wikipedia.org/wiki/Lists_of_black_holes "Lists of black holes") | [Black holes](https://en.wikipedia.org/wiki/List_of_black_holes "List of black holes") [Most massive](https://en.wikipedia.org/wiki/List_of_most_massive_black_holes "List of most massive black holes") [Nearest](https://en.wikipedia.org/wiki/List_of_nearest_known_black_holes "List of nearest known black holes") [Quasars](https://en.wikipedia.org/wiki/List_of_quasars "List of quasars") [Microquasars](https://en.wikipedia.org/wiki/List_of_microquasars "List of microquasars") | | Related | [Outline of black holes](https://en.wikipedia.org/wiki/Outline_of_black_holes "Outline of black holes") [Black Hole Initiative](https://en.wikipedia.org/wiki/Black_Hole_Initiative "Black Hole Initiative") [Black hole starship](https://en.wikipedia.org/wiki/Black_hole_starship "Black hole starship") [Black holes in fiction](https://en.wikipedia.org/wiki/Black_holes_in_fiction "Black holes in fiction") [Big Bang](https://en.wikipedia.org/wiki/Big_Bang "Big Bang") [Big Bounce](https://en.wikipedia.org/wiki/Big_Bounce "Big Bounce") [Compact star](https://en.wikipedia.org/wiki/Compact_star "Compact star") [Exotic star](https://en.wikipedia.org/wiki/Exotic_star "Exotic star") [Quark star](https://en.wikipedia.org/wiki/Quark_star "Quark star") [Preon star](https://en.wikipedia.org/wiki/Preon_star "Preon star") [Gravitational waves](https://en.wikipedia.org/wiki/Gravitational_waves "Gravitational waves") [Gamma-ray burst progenitors](https://en.wikipedia.org/wiki/Gamma-ray_burst_progenitors "Gamma-ray burst progenitors") [Gravity well](https://en.wikipedia.org/wiki/Gravity_well "Gravity well") [Hypercompact stellar system](https://en.wikipedia.org/wiki/Hypercompact_stellar_system "Hypercompact stellar system") [Membrane paradigm](https://en.wikipedia.org/wiki/Membrane_paradigm "Membrane paradigm") [Naked singularity](https://en.wikipedia.org/wiki/Naked_singularity "Naked singularity") [Population III star](https://en.wikipedia.org/wiki/Population_III_star "Population III star") [Supermassive star](https://en.wikipedia.org/wiki/Supermassive_star "Supermassive star") [Quasi-star](https://en.wikipedia.org/wiki/Quasi-star "Quasi-star") [Supermassive dark star](https://en.wikipedia.org/wiki/Dark_star_\(dark_matter\) "Dark star (dark matter)") [Rossi X-ray Timing Explorer](https://en.wikipedia.org/wiki/Rossi_X-ray_Timing_Explorer "Rossi X-ray Timing Explorer") [Superluminal motion](https://en.wikipedia.org/wiki/Superluminal_motion "Superluminal motion") [Timeline of black hole physics](https://en.wikipedia.org/wiki/Timeline_of_black_hole_physics "Timeline of black hole physics") [White hole](https://en.wikipedia.org/wiki/White_hole "White hole") [Wormhole](https://en.wikipedia.org/wiki/Wormhole "Wormhole") [Tidal disruption event](https://en.wikipedia.org/wiki/Tidal_disruption_event "Tidal disruption event") | | Notable | | | | | | [1ES 1927+654](https://en.wikipedia.org/wiki/1ES_1927%2B654 "1ES 1927+654") [3C 273](https://en.wikipedia.org/wiki/3C_273 "3C 273") [A0620-00](https://en.wikipedia.org/wiki/A0620-00 "A0620-00") [AT2018hyz](https://en.wikipedia.org/wiki/AT2018hyz "AT2018hyz") [Centaurus A](https://en.wikipedia.org/wiki/Centaurus_A "Centaurus A") [Cygnus X-1](https://en.wikipedia.org/wiki/Cygnus_X-1 "Cygnus X-1") [Gaia BH1](https://en.wikipedia.org/wiki/Gaia_BH1 "Gaia BH1") [Hercules A](https://en.wikipedia.org/wiki/Hercules_A "Hercules A") [Markarian 501](https://en.wikipedia.org/wiki/Markarian_501 "Markarian 501") [MS 0735.6+7421](https://en.wikipedia.org/wiki/MS_0735.6%2B7421 "MS 0735.6+7421") [NeVe 1](https://en.wikipedia.org/wiki/NeVe_1 "NeVe 1") [OJ 287](https://en.wikipedia.org/wiki/OJ_287 "OJ 287") [Phoenix Cluster](https://en.wikipedia.org/wiki/Phoenix_Cluster "Phoenix Cluster") [PKS 1302-102](https://en.wikipedia.org/wiki/PKS_1302-102 "PKS 1302-102") [PSO J030947.49+271757.31](https://en.wikipedia.org/wiki/PSO_J030947.49%2B271757.31 "PSO J030947.49+271757.31") [Q0906+6930](https://en.wikipedia.org/wiki/Q0906%2B6930 "Q0906+6930") [Sagittarius A\*]() [SDSS J0849+1114](https://en.wikipedia.org/wiki/SDSS_J0849%2B1114 "SDSS J0849+1114") [Swift J1644+57](https://en.wikipedia.org/wiki/Swift_J1644%2B57 "Swift J1644+57") [TON 618](https://en.wikipedia.org/wiki/TON_618 "TON 618") [ULAS J1342+0928](https://en.wikipedia.org/wiki/ULAS_J1342%2B0928 "ULAS J1342+0928") [XTE J1118+480](https://en.wikipedia.org/wiki/XTE_J1118%2B480 "XTE J1118+480") [XTE J1650-500](https://en.wikipedia.org/wiki/XTE_J1650-500 "XTE J1650-500") | [![](https://upload.wikimedia.org/wikipedia/commons/thumb/4/4f/Black_hole_-_Messier_87_crop_max_res.jpg/120px-Black_hole_-_Messier_87_crop_max_res.jpg)](https://en.wikipedia.org/wiki/File:Black_hole_-_Messier_87_crop_max_res.jpg) | | ![](https://upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/20px-Symbol_category_class.svg.png) [Category](https://en.wikipedia.org/wiki/Category:Black_holes "Category:Black holes") [![](https://upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/20px-Commons-logo.svg.png)](https://en.wikipedia.org/wiki/File:Commons-logo.svg "Commons page") [Commons](https://commons.wikimedia.org/wiki/Category:Black_holes "commons:Category:Black holes") | | | [v](https://en.wikipedia.org/wiki/Template:Milky_Way "Template:Milky Way") [t](https://en.wikipedia.org/wiki/Template_talk:Milky_Way "Template talk:Milky Way") [e](https://en.wikipedia.org/wiki/Special:EditPage/Template:Milky_Way "Special:EditPage/Template:Milky Way")[Milky Way](https://en.wikipedia.org/wiki/Milky_Way "Milky Way") | | | |---|---|---| | Location | [Milky Way](https://en.wikipedia.org/wiki/Milky_Way "Milky Way") → [Milky Way subgroup](https://en.wikipedia.org/wiki/Satellite_galaxies_of_the_Milky_Way "Satellite galaxies of the Milky Way") → [Local Group](https://en.wikipedia.org/wiki/Local_Group "Local Group") → [Local Sheet](https://en.wikipedia.org/wiki/Local_Sheet "Local Sheet") → [Local Volume](https://en.wikipedia.org/wiki/Local_Volume "Local Volume") → [Virgo Supercluster](https://en.wikipedia.org/wiki/Virgo_Supercluster "Virgo Supercluster") → [Laniakea Supercluster](https://en.wikipedia.org/wiki/Laniakea_Supercluster "Laniakea Supercluster") → [Pisces–Cetus Supercluster Complex](https://en.wikipedia.org/wiki/Pisces%E2%80%93Cetus_Supercluster_Complex "Pisces–Cetus Supercluster Complex") → [Local Hole](https://en.wikipedia.org/wiki/Local_Hole "Local Hole") → [Observable universe](https://en.wikipedia.org/wiki/Observable_universe "Observable universe") → [Universe](https://en.wikipedia.org/wiki/Universe "Universe") Each arrow (→) may be read as "within" or "part of". | [![The Milky Way Galaxy](https://upload.wikimedia.org/wikipedia/commons/thumb/4/4f/Artist%E2%80%99s_impression_of_the_Milky_Way.jpg/120px-Artist%E2%80%99s_impression_of_the_Milky_Way.jpg)](https://en.wikipedia.org/wiki/File:Artist%E2%80%99s_impression_of_the_Milky_Way.jpg "The Milky Way Galaxy") The Milky Way Galaxy | | Structure | | | | | | | | [Galactic Center](https://en.wikipedia.org/wiki/Galactic_Center "Galactic Center") | [Sagittarius A](https://en.wikipedia.org/wiki/Sagittarius_A "Sagittarius A") [Sagittarius A\*]() [Fermi bubbles](https://en.wikipedia.org/wiki/Fermi_bubble "Fermi bubble") [Supermassive black hole](https://en.wikipedia.org/wiki/Supermassive_black_hole "Supermassive black hole") [Galactic Center filaments](https://en.wikipedia.org/wiki/Galactic_Center_filament "Galactic Center filament") [Galactic Center GeV excess](https://en.wikipedia.org/wiki/Galactic_Center_GeV_excess "Galactic Center GeV excess") [Galactic Center Radio Arc](https://en.wikipedia.org/wiki/Galactic_Center_Radio_Arc "Galactic Center Radio Arc") | | | [Disk](https://en.wikipedia.org/wiki/Galactic_disc#Structure_of_the_Milky_Way_Disc "Galactic disc") | [Carina–Sagittarius](https://en.wikipedia.org/wiki/Carina%E2%80%93Sagittarius_Arm "Carina–Sagittarius Arm") [Norma–Cygnus](https://en.wikipedia.org/wiki/Norma_Arm "Norma Arm") [Orion–Cygnus](https://en.wikipedia.org/wiki/Orion_Arm "Orion Arm") [Perseus](https://en.wikipedia.org/wiki/Perseus_Arm "Perseus Arm") [Scutum–Centaurus](https://en.wikipedia.org/wiki/Scutum%E2%80%93Centaurus_Arm "Scutum–Centaurus Arm") [Near 3 kpc Arm](https://en.wikipedia.org/wiki/Near_3_kpc_Arm "Near 3 kpc Arm") [Far 3 kpc Arm](https://en.wikipedia.org/wiki/Far_3_kpc_Arm "Far 3 kpc Arm") | | | [Halo](https://en.wikipedia.org/wiki/Galactic_halo "Galactic halo") | [Aquarius Stream](https://en.wikipedia.org/wiki/Aquarius_Stream "Aquarius Stream") [Fimbulthul stream](https://en.wikipedia.org/wiki/Fimbulthul_stream "Fimbulthul stream") [Gaia Sausage](https://en.wikipedia.org/wiki/Gaia_Sausage "Gaia Sausage") [Helmi stream](https://en.wikipedia.org/wiki/Helmi_stream "Helmi stream") [Magellanic Stream](https://en.wikipedia.org/wiki/Magellanic_Stream "Magellanic Stream") [Monoceros Ring](https://en.wikipedia.org/wiki/Monoceros_Ring "Monoceros Ring") [Palomar 5](https://en.wikipedia.org/wiki/Palomar_5 "Palomar 5") stream [Pisces–Eridanus stream](https://en.wikipedia.org/wiki/Pisces%E2%80%93Eridanus_stellar_stream "Pisces–Eridanus stellar stream") [Sagittarius Stream](https://en.wikipedia.org/wiki/Sagittarius_Stream "Sagittarius Stream") [Virgo Stream](https://en.wikipedia.org/wiki/Virgo_Stellar_Stream "Virgo Stellar Stream") | | | [Satellite galaxies](https://en.wikipedia.org/wiki/Satellite_galaxies_of_the_Milky_Way "Satellite galaxies of the Milky Way") | | | | | | | | [Magellanic Clouds](https://en.wikipedia.org/wiki/Magellanic_Clouds "Magellanic Clouds") | [Large Magellanic Cloud](https://en.wikipedia.org/wiki/Large_Magellanic_Cloud "Large Magellanic Cloud") [Small Magellanic Cloud](https://en.wikipedia.org/wiki/Small_Magellanic_Cloud "Small Magellanic Cloud") [Magellanic Bridge](https://en.wikipedia.org/wiki/Magellanic_Bridge "Magellanic Bridge") | | | [Dwarfs](https://en.wikipedia.org/wiki/Dwarf_galaxy "Dwarf galaxy") | [Antlia II](https://en.wikipedia.org/wiki/Antlia_II "Antlia II") [Boötes I](https://en.wikipedia.org/wiki/Bo%C3%B6tes_I "Boötes I") [Boötes II](https://en.wikipedia.org/wiki/Bo%C3%B6tes_II "Boötes II") [Boötes III](https://en.wikipedia.org/wiki/Bo%C3%B6tes_III "Boötes III") [Canes Venatici I](https://en.wikipedia.org/wiki/Canes_Venatici_I "Canes Venatici I") [Canes Venatici II](https://en.wikipedia.org/wiki/Canes_Venatici_II "Canes Venatici II") [Canis Major](https://en.wikipedia.org/wiki/Canis_Major_Overdensity "Canis Major Overdensity") [Carina](https://en.wikipedia.org/wiki/Carina_Dwarf_Spheroidal_Galaxy "Carina Dwarf Spheroidal Galaxy") [Coma Berenices](https://en.wikipedia.org/wiki/Coma_Berenices_\(dwarf_galaxy\) "Coma Berenices (dwarf galaxy)") [Crater 2](https://en.wikipedia.org/wiki/Crater_2_Dwarf "Crater 2 Dwarf") [Draco](https://en.wikipedia.org/wiki/Draco_Dwarf "Draco Dwarf") [Eridanus II](https://en.wikipedia.org/wiki/Eridanus_II "Eridanus II") [Fornax](https://en.wikipedia.org/wiki/Fornax_Dwarf "Fornax Dwarf") [Hercules](https://en.wikipedia.org/wiki/Hercules_\(dwarf_galaxy\) "Hercules (dwarf galaxy)") [Leo I](https://en.wikipedia.org/wiki/Leo_I_\(dwarf_galaxy\) "Leo I (dwarf galaxy)") [Leo II](https://en.wikipedia.org/wiki/Leo_II_\(dwarf_galaxy\) "Leo II (dwarf galaxy)") [Leo IV](https://en.wikipedia.org/wiki/Leo_IV_\(dwarf_galaxy\) "Leo IV (dwarf galaxy)") [Leo V](https://en.wikipedia.org/wiki/Leo_V_\(dwarf_galaxy\) "Leo V (dwarf galaxy)") [Leo T](https://en.wikipedia.org/wiki/Leo_T "Leo T") [Phoenix](https://en.wikipedia.org/wiki/Phoenix_Dwarf "Phoenix Dwarf") [Pisces Overdensity](https://en.wikipedia.org/wiki/Pisces_Overdensity "Pisces Overdensity") [Pisces II](https://en.wikipedia.org/wiki/Pisces_II "Pisces II") [Reticulum II](https://en.wikipedia.org/wiki/Reticulum_II "Reticulum II") [Sagittarius Spheroidal](https://en.wikipedia.org/wiki/Sagittarius_Dwarf_Spheroidal_Galaxy "Sagittarius Dwarf Spheroidal Galaxy") [Segue 1](https://en.wikipedia.org/wiki/Segue_1 "Segue 1") [Segue 2](https://en.wikipedia.org/wiki/Segue_2 "Segue 2") [Sculptor](https://en.wikipedia.org/wiki/Sculptor_Dwarf_Galaxy "Sculptor Dwarf Galaxy") [Sextans](https://en.wikipedia.org/wiki/Sextans_Dwarf_Spheroidal "Sextans Dwarf Spheroidal") [Triangulum II](https://en.wikipedia.org/wiki/Triangulum_II "Triangulum II") [Ursa Major I](https://en.wikipedia.org/wiki/Ursa_Major_I_Dwarf "Ursa Major I Dwarf") [Ursa Major II](https://en.wikipedia.org/wiki/Ursa_Major_II_Dwarf "Ursa Major II Dwarf") [Ursa Major III](https://en.wikipedia.org/wiki/Ursa_Major_III "Ursa Major III") [Ursa Minor](https://en.wikipedia.org/wiki/Ursa_Minor_Dwarf "Ursa Minor Dwarf") [Virgo I](https://en.wikipedia.org/wiki/Virgo_I "Virgo I") [Willman 1](https://en.wikipedia.org/wiki/Willman_1 "Willman 1") | | | Related | [Alternate names](https://en.wikipedia.org/wiki/List_of_names_for_the_Milky_Way "List of names for the Milky Way") [Andromeda–Milky Way collision](https://en.wikipedia.org/wiki/Andromeda%E2%80%93Milky_Way_collision "Andromeda–Milky Way collision") [Baade's Window](https://en.wikipedia.org/wiki/Baade%27s_Window "Baade's Window") [In mythology](https://en.wikipedia.org/wiki/Milky_Way_\(mythology\) "Milky Way (mythology)") [Zone of Avoidance](https://en.wikipedia.org/wiki/Zone_of_Avoidance "Zone of Avoidance") | | | [![](https://upload.wikimedia.org/wikipedia/en/thumb/e/e2/Symbol_portal_class.svg/20px-Symbol_portal_class.svg.png)](https://en.wikipedia.org/wiki/File:Symbol_portal_class.svg "Portal") [Astronomy portal](https://en.wikipedia.org/wiki/Portal:Astronomy "Portal:Astronomy") ![](https://upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/20px-Symbol_category_class.svg.png) [Category](https://en.wikipedia.org/wiki/Category:Milky_Way "Category:Milky Way") | | | | [v](https://en.wikipedia.org/wiki/Template:Sagittarius_\(constellation\) "Template:Sagittarius (constellation)") [t](https://en.wikipedia.org/wiki/Template_talk:Sagittarius_\(constellation\) "Template talk:Sagittarius (constellation)") [e](https://en.wikipedia.org/wiki/Special:EditPage/Template:Sagittarius_\(constellation\) "Special:EditPage/Template:Sagittarius (constellation)")[Constellation of Sagittarius](https://en.wikipedia.org/wiki/Sagittarius_\(constellation\) "Sagittarius (constellation)") | | |---|---| | [List of stars in Sagittarius](https://en.wikipedia.org/wiki/List_of_stars_in_Sagittarius "List of stars in Sagittarius") [Galactic Center](https://en.wikipedia.org/wiki/Galactic_Center "Galactic Center") [Central Molecular Zone](https://en.wikipedia.org/wiki/Central_Molecular_Zone "Central Molecular Zone") [Large Sagittarius Star Cloud](https://en.wikipedia.org/wiki/Large_Sagittarius_Star_Cloud "Large Sagittarius Star Cloud") [Sagittarius A\*]() [Sagittarius in Chinese astronomy](https://en.wikipedia.org/wiki/Sagittarius_in_Chinese_astronomy "Sagittarius in Chinese astronomy") [Wow! signal](https://en.wikipedia.org/wiki/Wow!_signal "Wow! signal") | | | [Stars](https://en.wikipedia.org/wiki/Star "Star") | | | | | | [Bayer](https://en.wikipedia.org/wiki/Bayer_designation "Bayer designation") | [α (Rukbat)](https://en.wikipedia.org/wiki/Alpha_Sagittarii "Alpha Sagittarii") [ÎČ1 (Arkab Prior)](https://en.wikipedia.org/wiki/Beta1_Sagittarii "Beta1 Sagittarii") [ÎČ2 (Arkab Posterior)](https://en.wikipedia.org/wiki/Beta2_Sagittarii "Beta2 Sagittarii") [Îł1 (W)](https://en.wikipedia.org/wiki/W_Sagittarii "W Sagittarii") [Îł2 (Alnasl)](https://en.wikipedia.org/wiki/Gamma2_Sagittarii "Gamma2 Sagittarii") [ÎŽ (Kaus Media)](https://en.wikipedia.org/wiki/Delta_Sagittarii "Delta Sagittarii") [Δ (Kaus Australis)](https://en.wikipedia.org/wiki/Epsilon_Sagittarii "Epsilon Sagittarii") [ζ (Ascella)](https://en.wikipedia.org/wiki/Zeta_Sagittarii "Zeta Sagittarii") [η](https://en.wikipedia.org/wiki/Eta_Sagittarii "Eta Sagittarii") [Ξ1](https://en.wikipedia.org/wiki/Theta1_Sagittarii "Theta1 Sagittarii") [Ξ2](https://en.wikipedia.org/wiki/Theta2_Sagittarii "Theta2 Sagittarii") [Îč](https://en.wikipedia.org/wiki/Iota_Sagittarii "Iota Sagittarii") [Îș1](https://en.wikipedia.org/wiki/Kappa1_Sagittarii "Kappa1 Sagittarii") [Îș2](https://en.wikipedia.org/wiki/Kappa2_Sagittarii "Kappa2 Sagittarii") [λ (Kaus Borealis)](https://en.wikipedia.org/wiki/Lambda_Sagittarii "Lambda Sagittarii") [ÎŒ (Polis)](https://en.wikipedia.org/wiki/Mu_Sagittarii "Mu Sagittarii") [Îœ1 (Ainalrami)](https://en.wikipedia.org/wiki/Nu1_Sagittarii "Nu1 Sagittarii") [Îœ2](https://en.wikipedia.org/wiki/Nu2_Sagittarii "Nu2 Sagittarii") [Ο1](https://en.wikipedia.org/wiki/Xi1_Sagittarii "Xi1 Sagittarii") [Ο2](https://en.wikipedia.org/wiki/Xi2_Sagittarii "Xi2 Sagittarii") [Îż](https://en.wikipedia.org/wiki/Omicron_Sagittarii "Omicron Sagittarii") [π (Albaldah)](https://en.wikipedia.org/wiki/Pi_Sagittarii "Pi Sagittarii") [ρ1](https://en.wikipedia.org/wiki/Rho1_Sagittarii "Rho1 Sagittarii") [ρ2](https://en.wikipedia.org/wiki/Rho2_Sagittarii "Rho2 Sagittarii") [σ (Nunki)](https://en.wikipedia.org/wiki/Sigma_Sagittarii "Sigma Sagittarii") [τ](https://en.wikipedia.org/wiki/Tau_Sagittarii "Tau Sagittarii") [υ](https://en.wikipedia.org/wiki/Upsilon_Sagittarii "Upsilon Sagittarii") [φ](https://en.wikipedia.org/wiki/Phi_Sagittarii "Phi Sagittarii") [χ1](https://en.wikipedia.org/wiki/Chi1_Sagittarii "Chi1 Sagittarii") [χ2](https://en.wikipedia.org/wiki/Chi2_Sagittarii "Chi2 Sagittarii") [χ3](https://en.wikipedia.org/wiki/Chi3_Sagittarii "Chi3 Sagittarii") [ψ](https://en.wikipedia.org/wiki/Psi_Sagittarii "Psi Sagittarii") [ω (Terebellum)](https://en.wikipedia.org/wiki/Omega_Sagittarii "Omega Sagittarii") | | [Flamsteed](https://en.wikipedia.org/wiki/Flamsteed_designation "Flamsteed designation") | [1](https://en.wikipedia.org/wiki/HR_6801 "HR 6801") [3](https://en.wikipedia.org/wiki/X_Sagittarii "X Sagittarii") [4](https://en.wikipedia.org/wiki/4_Sagittarii "4 Sagittarii") [6](https://en.wikipedia.org/wiki/6_Sagittarii "6 Sagittarii") [7](https://en.wikipedia.org/wiki/7_Sagittarii "7 Sagittarii") [9](https://en.wikipedia.org/wiki/9_Sagittarii "9 Sagittarii") [11](https://en.wikipedia.org/wiki/V3903_Sagittarii "V3903 Sagittarii") [14](https://en.wikipedia.org/wiki/14_Sagittarii "14 Sagittarii") [15](https://en.wikipedia.org/wiki/15_Sagittarii "15 Sagittarii") [16](https://en.wikipedia.org/wiki/16_Sagittarii "16 Sagittarii") [17](https://en.wikipedia.org/wiki/17_Sagittarii "17 Sagittarii") [18](https://en.wikipedia.org/wiki/18_Sagittarii "18 Sagittarii") [21](https://en.wikipedia.org/wiki/21_Sagittarii "21 Sagittarii") [43 (d)](https://en.wikipedia.org/wiki/43_Sagittarii "43 Sagittarii") [52 (h2)](https://en.wikipedia.org/wiki/52_Sagittarii "52 Sagittarii") [56 (f)](https://en.wikipedia.org/wiki/56_Sagittarii "56 Sagittarii") [59 (b)](https://en.wikipedia.org/wiki/59_Sagittarii "59 Sagittarii") [60 (A)](https://en.wikipedia.org/wiki/60_Sagittarii "60 Sagittarii") [62 (c)](https://en.wikipedia.org/wiki/62_Sagittarii "62 Sagittarii") *[63 Oph](https://en.wikipedia.org/wiki/63_Ophiuchi "63 Ophiuchi")* | | [Variable](https://en.wikipedia.org/wiki/Variable_star_designation "Variable star designation") | [U](https://en.wikipedia.org/wiki/U_Sagittarii "U Sagittarii") [Y](https://en.wikipedia.org/wiki/Y_Sagittarii "Y Sagittarii") [RS](https://en.wikipedia.org/wiki/RS_Sagittarii "RS Sagittarii") [RY](https://en.wikipedia.org/wiki/RY_Sagittarii "RY Sagittarii") [VX](https://en.wikipedia.org/wiki/VX_Sagittarii "VX Sagittarii") [KW](https://en.wikipedia.org/wiki/KW_Sagittarii "KW Sagittarii") [V348](https://en.wikipedia.org/wiki/V348_Sagittarii "V348 Sagittarii") [V356](https://en.wikipedia.org/wiki/V356_Sagittarii "V356 Sagittarii") [V630](https://en.wikipedia.org/wiki/V630_Sagittarii "V630 Sagittarii") [V725](https://en.wikipedia.org/wiki/V725_Sagittarii "V725 Sagittarii") [V1017](https://en.wikipedia.org/wiki/V1017_Sagittarii "V1017 Sagittarii") [V1059](https://en.wikipedia.org/wiki/V1059_Sagittarii "V1059 Sagittarii") [V3961](https://en.wikipedia.org/wiki/HD_187474 "HD 187474") [V4024](https://en.wikipedia.org/wiki/V4024_Sagittarii "V4024 Sagittarii") [V4029](https://en.wikipedia.org/wiki/HD_168607 "HD 168607") [V4030](https://en.wikipedia.org/wiki/HD_168625 "HD 168625") [V4046](https://en.wikipedia.org/wiki/V4046_Sagittarii "V4046 Sagittarii") [V4199](https://en.wikipedia.org/wiki/V4199_Sagittarii "V4199 Sagittarii") [V4200](https://en.wikipedia.org/wiki/HR_7578 "HR 7578") [V4332](https://en.wikipedia.org/wiki/V4332_Sagittarii "V4332 Sagittarii") [V4334](https://en.wikipedia.org/wiki/Sakurai%27s_Object "Sakurai's Object") [V4375](https://en.wikipedia.org/wiki/HD_316285 "HD 316285") [V4381](https://en.wikipedia.org/wiki/V4381_Sagittarii "V4381 Sagittarii") [V4580](https://en.wikipedia.org/wiki/SAX_J1808.4%E2%88%923658 "SAX J1808.4−3658") [V4641](https://en.wikipedia.org/wiki/V4641_Sagittarii "V4641 Sagittarii") [V4647 (Pistol Star)](https://en.wikipedia.org/wiki/Pistol_Star "Pistol Star") [V4650](https://en.wikipedia.org/wiki/V4650_Sagittarii "V4650 Sagittarii") [V4743](https://en.wikipedia.org/wiki/V4743_Sagittarii "V4743 Sagittarii") [V4998](https://en.wikipedia.org/wiki/V4998_Sagittarii "V4998 Sagittarii") [V5125](https://en.wikipedia.org/wiki/OGLE-TR-10 "OGLE-TR-10") [V5157](https://en.wikipedia.org/wiki/OGLE-TR-56 "OGLE-TR-56") [V5652 (Gumala)](https://en.wikipedia.org/wiki/HD_179949 "HD 179949") [V5668](https://en.wikipedia.org/wiki/V5668_Sagittarii "V5668 Sagittarii") [V5856](https://en.wikipedia.org/wiki/V5856_Sagittarii "V5856 Sagittarii") | | [HR](https://en.wikipedia.org/wiki/Bright_Star_Catalogue "Bright Star Catalogue") | [6748](https://en.wikipedia.org/wiki/HD_165185 "HD 165185") [6762](https://en.wikipedia.org/wiki/HD_165516 "HD 165516") [6766](https://en.wikipedia.org/wiki/HD_165634 "HD 165634") [6836](https://en.wikipedia.org/wiki/HD_167665 "HD 167665") [6842](https://en.wikipedia.org/wiki/HD_167818 "HD 167818") [6907](https://en.wikipedia.org/wiki/HD_169830 "HD 169830") [6998](https://en.wikipedia.org/wiki/HD_172051 "HD 172051") [7029](https://en.wikipedia.org/wiki/HD_172910 "HD 172910") [7355](https://en.wikipedia.org/wiki/HR_7355 "HR 7355") [7380](https://en.wikipedia.org/wiki/HD_182681 "HD 182681") [7631](https://en.wikipedia.org/wiki/HD_189245 "HD 189245") [7652](https://en.wikipedia.org/wiki/HD_189831 "HD 189831") [7659](https://en.wikipedia.org/wiki/HD_190056 "HD 190056") [7703](https://en.wikipedia.org/wiki/HR_7703 "HR 7703") | | [HD](https://en.wikipedia.org/wiki/Henry_Draper_Catalogue "Henry Draper Catalogue") | [163296](https://en.wikipedia.org/wiki/HD_163296 "HD 163296") [164270](https://en.wikipedia.org/wiki/HD_164270 "HD 164270") [164604 (Pincoya)](https://en.wikipedia.org/wiki/HD_164604 "HD 164604") [166191](https://en.wikipedia.org/wiki/HD_166191 "HD 166191") [169142](https://en.wikipedia.org/wiki/HD_169142 "HD 169142") [170657](https://en.wikipedia.org/wiki/HD_170657 "HD 170657") [171238](https://en.wikipedia.org/wiki/HD_171238 "HD 171238") [177765](https://en.wikipedia.org/wiki/HD_177765 "HD 177765") [180902](https://en.wikipedia.org/wiki/HD_180902 "HD 180902") [181342 (Belel)](https://en.wikipedia.org/wiki/HD_181342 "HD 181342") [181720 (Sika)](https://en.wikipedia.org/wiki/HD_181720 "HD 181720") [187085](https://en.wikipedia.org/wiki/HD_187085 "HD 187085") [190647](https://en.wikipedia.org/wiki/HD_190647 "HD 190647") [316285](https://en.wikipedia.org/wiki/HD_316285 "HD 316285") | | Other | [2MASS J18352154−3123385](https://en.wikipedia.org/wiki/2MASS_J18352154%E2%88%923123385 "2MASS J18352154−3123385") [2MASS J19281982−2640123](https://en.wikipedia.org/wiki/2MASS_19281982%E2%88%922640123 "2MASS 19281982−2640123") [Bursting Pulsar](https://en.wikipedia.org/wiki/Bursting_Pulsar "Bursting Pulsar") [CEN 16](https://en.wikipedia.org/wiki/CEN_16 "CEN 16") [CWISEP J1935−1546](https://en.wikipedia.org/wiki/CWISEP_J1935%E2%88%921546 "CWISEP J1935−1546") [D9](https://en.wikipedia.org/wiki/D9_\(star\) "D9 (star)") [GCIRS 7](https://en.wikipedia.org/wiki/GCIRS_7 "GCIRS 7") [GCIRS 8\*](https://en.wikipedia.org/wiki/GCIRS_8* "GCIRS 8*") [GCIRS 13E](https://en.wikipedia.org/wiki/GCIRS_13E "GCIRS 13E") [GCIRS 16SW](https://en.wikipedia.org/wiki/GCIRS_16SW "GCIRS 16SW") [Gomez's Hamburger](https://en.wikipedia.org/wiki/Gomez%27s_Hamburger "Gomez's Hamburger") [G0.238−0.071](https://en.wikipedia.org/wiki/G0.238%E2%88%920.071 "G0.238−0.071") [HATS-36](https://en.wikipedia.org/wiki/HATS-36 "HATS-36") [IRAS 17423−1755](https://en.wikipedia.org/wiki/IRAS_17423%E2%88%921755 "IRAS 17423−1755") [IRAS 18162−2048](https://en.wikipedia.org/wiki/IRAS_18162%E2%88%922048 "IRAS 18162−2048") [K2-2016-BLG-0005L](https://en.wikipedia.org/wiki/K2-2016-BLG-0005L "K2-2016-BLG-0005L") [KMT-2020-BLG-0414L](https://en.wikipedia.org/wiki/KMT-2020-BLG-0414L "KMT-2020-BLG-0414L") [KMT-2024-BLG-0404L](https://en.wikipedia.org/wiki/KMT-2024-BLG-0404L "KMT-2024-BLG-0404L") [LBV 1806−20](https://en.wikipedia.org/wiki/LBV_1806%E2%88%9220 "LBV 1806−20") [MACHO 176.18833.411](https://en.wikipedia.org/wiki/MACHO_176.18833.411 "MACHO 176.18833.411") [MACHO-96-BLG-5](https://en.wikipedia.org/wiki/MACHO-96-BLG-5 "MACHO-96-BLG-5") [MACHO-1997-BLG-41](https://en.wikipedia.org/wiki/MACHO-1997-BLG-41 "MACHO-1997-BLG-41") [MACHO-98-BLG-35](https://en.wikipedia.org/wiki/MACHO-98-BLG-35 "MACHO-98-BLG-35") [MOA-2007-BLG-192L](https://en.wikipedia.org/wiki/MOA-2007-BLG-192L "MOA-2007-BLG-192L") [MOA-2007-BLG-400L](https://en.wikipedia.org/wiki/MOA-2007-BLG-400L "MOA-2007-BLG-400L") [MOA-2009-BLG-387L](https://en.wikipedia.org/wiki/MOA-2009-BLG-387L "MOA-2009-BLG-387L") [MOA-2010-BLG-477L](https://en.wikipedia.org/wiki/MOA-2010-BLG-477L "MOA-2010-BLG-477L") [MOA-2011-BLG-262L](https://en.wikipedia.org/wiki/MOA-2011-BLG-262L "MOA-2011-BLG-262L") [NGC 300 X-1](https://en.wikipedia.org/wiki/NGC_300_X-1 "NGC 300 X-1") [NGC 6822-WR 12](https://en.wikipedia.org/wiki/NGC_6822-WR_12 "NGC 6822-WR 12") [OGLE-2003-BLG-235L](https://en.wikipedia.org/wiki/OGLE-2003-BLG-235L "OGLE-2003-BLG-235L") [OGLE-2005-BLG-169L](https://en.wikipedia.org/wiki/OGLE-2005-BLG-169L "OGLE-2005-BLG-169L") [OGLE-2011-BLG-0462](https://en.wikipedia.org/wiki/OGLE-2011-BLG-0462 "OGLE-2011-BLG-0462") [OGLE-2016-BLG-0007L](https://en.wikipedia.org/wiki/OGLE-2016-BLG-0007L "OGLE-2016-BLG-0007L") [PSR J1747−2958](https://en.wikipedia.org/wiki/PSR_J1747%E2%88%922958 "PSR J1747−2958") [PSR J1748−2021B](https://en.wikipedia.org/wiki/PSR_J1748%E2%88%922021B "PSR J1748−2021B") [PSR J1748−2446ad](https://en.wikipedia.org/wiki/PSR_J1748%E2%88%922446ad "PSR J1748−2446ad") [PSR J1930−1852](https://en.wikipedia.org/wiki/PSR_J1930%E2%88%921852 "PSR J1930−1852") [Ross 154](https://en.wikipedia.org/wiki/Ross_154 "Ross 154") [S2](https://en.wikipedia.org/wiki/S2_\(star\) "S2 (star)") [S55](https://en.wikipedia.org/wiki/S55_\(star\) "S55 (star)") [S62](https://en.wikipedia.org/wiki/S62_\(star\) "S62 (star)") [S4716](https://en.wikipedia.org/wiki/S4716 "S4716") [SAX J1808.4−3658](https://en.wikipedia.org/wiki/SAX_J1808.4%E2%88%923658 "SAX J1808.4−3658") [SGR J1745−2900](https://en.wikipedia.org/wiki/SGR_J1745%E2%88%922900 "SGR J1745−2900") [SGR 1806−20](https://en.wikipedia.org/wiki/SGR_1806%E2%88%9220 "SGR 1806−20") [SWEEPS J175853.92−291120.6](https://en.wikipedia.org/wiki/SWEEPS_J175853.92%E2%88%92291120.6 "SWEEPS J175853.92−291120.6") [SWEEPS J175902.67−291153.5](https://en.wikipedia.org/wiki/SWEEPS_J175902.67%E2%88%92291153.5 "SWEEPS J175902.67−291153.5") [SWIFT J1745−26](https://en.wikipedia.org/wiki/SWIFT_J1745%E2%88%9226 "SWIFT J1745−26") [SWIFT J1756.9−2508](https://en.wikipedia.org/wiki/SWIFT_J1756.9%E2%88%922508 "SWIFT J1756.9−2508") [SWIFT J1818.0−1607](https://en.wikipedia.org/wiki/SWIFT_J1818.0%E2%88%921607 "SWIFT J1818.0−1607") [W33A](https://en.wikipedia.org/wiki/W33A "W33A") [WASP-67](https://en.wikipedia.org/wiki/WASP-67 "WASP-67") [WD 0032−317](https://en.wikipedia.org/wiki/WD_0032%E2%88%92317 "WD 0032−317") [WR 101-2](https://en.wikipedia.org/wiki/WR_101-2 "WR 101-2") [WR 102](https://en.wikipedia.org/wiki/WR_102 "WR 102") [WR 102c](https://en.wikipedia.org/wiki/WR_102c "WR 102c") [WR 102ea](https://en.wikipedia.org/wiki/WR_102ea "WR 102ea") [WR 102ka](https://en.wikipedia.org/wiki/WR_102ka "WR 102ka") [WR 104](https://en.wikipedia.org/wiki/WR_104 "WR 104") [WR 111](https://en.wikipedia.org/wiki/WR_111 "WR 111") | | | | | [Exoplanets](https://en.wikipedia.org/wiki/Exoplanet "Exoplanet") | [HATS-36b](https://en.wikipedia.org/wiki/HATS-36b "HATS-36b") [HD 164604 b (Caleuche)](https://en.wikipedia.org/wiki/HD_164604_b "HD 164604 b") [HD 169830 b](https://en.wikipedia.org/wiki/HD_169830_b "HD 169830 b") [c](https://en.wikipedia.org/wiki/HD_169830_c "HD 169830 c") [HD 171238 b](https://en.wikipedia.org/wiki/HD_171238_b "HD 171238 b") [HD 179949 b (Mastika)](https://en.wikipedia.org/wiki/HD_179949_b "HD 179949 b") [HD 180902 b](https://en.wikipedia.org/wiki/HD_180902_b "HD 180902 b") [HD 181342 b (Dopere)](https://en.wikipedia.org/wiki/HD_181342_b "HD 181342 b") [HD 181720 b (Toge)](https://en.wikipedia.org/wiki/HD_181720_b "HD 181720 b") [HD 187085 b](https://en.wikipedia.org/wiki/HD_187085_b "HD 187085 b") [HD 190647 b](https://en.wikipedia.org/wiki/HD_190647_b "HD 190647 b") [K2-2016-BLG-0005Lb](https://en.wikipedia.org/wiki/K2-2016-BLG-0005Lb "K2-2016-BLG-0005Lb") [KMT-2016-BLG-1337Lb](https://en.wikipedia.org/wiki/KMT-2016-BLG-1337Lb "KMT-2016-BLG-1337Lb") [KMT-2022-BLG-0440L b](https://en.wikipedia.org/wiki/KMT-2022-BLG-0440L_b "KMT-2022-BLG-0440L b") [KMT-2024-BLG-0404Lb](https://en.wikipedia.org/wiki/KMT-2024-BLG-0404Lb "KMT-2024-BLG-0404Lb") [MOA-2007-BLG-192Lb](https://en.wikipedia.org/wiki/MOA-2007-BLG-192Lb "MOA-2007-BLG-192Lb") [MOA-2007-BLG-400Lb](https://en.wikipedia.org/wiki/MOA-2007-BLG-400Lb "MOA-2007-BLG-400Lb") [MOA-2009-BLG-387Lb](https://en.wikipedia.org/wiki/MOA-2009-BLG-387Lb "MOA-2009-BLG-387Lb") [OGLE-2003-BLG-235Lb](https://en.wikipedia.org/wiki/OGLE-2003-BLG-235Lb "OGLE-2003-BLG-235Lb") [OGLE-2005-BLG-169Lb](https://en.wikipedia.org/wiki/OGLE-2005-BLG-169Lb "OGLE-2005-BLG-169Lb") [OGLE-2007-BLG-349Lb](https://en.wikipedia.org/wiki/OGLE-2007-BLG-349Lb "OGLE-2007-BLG-349Lb") [OGLE-2016-BLG-0007Lb](https://en.wikipedia.org/wiki/OGLE-2016-BLG-0007Lb "OGLE-2016-BLG-0007Lb") [OGLE-2016-BLG-1190Lb](https://en.wikipedia.org/wiki/OGLE-2016-BLG-1190Lb "OGLE-2016-BLG-1190Lb") [OGLE-2016-BLG-1928L](https://en.wikipedia.org/wiki/OGLE-2016-BLG-1928L "OGLE-2016-BLG-1928L") [OGLE-TR-10b](https://en.wikipedia.org/wiki/OGLE-TR-10b "OGLE-TR-10b") [OGLE-TR-56b](https://en.wikipedia.org/wiki/OGLE-TR-56b "OGLE-TR-56b") [SWEEPS-04](https://en.wikipedia.org/wiki/SWEEPS-04 "SWEEPS-04") [SWEEPS-10](https://en.wikipedia.org/wiki/SWEEPS-10 "SWEEPS-10") (unconfirmed) [SWEEPS-11](https://en.wikipedia.org/wiki/SWEEPS-11 "SWEEPS-11") | | [Star clusters](https://en.wikipedia.org/wiki/Star_cluster "Star cluster") | | | | | | [NGC](https://en.wikipedia.org/wiki/New_General_Catalogue "New General Catalogue") | [6440](https://en.wikipedia.org/wiki/NGC_6440 "NGC 6440") [6520](https://en.wikipedia.org/wiki/NGC_6520 "NGC 6520") [6522](https://en.wikipedia.org/wiki/NGC_6522 "NGC 6522") [6528](https://en.wikipedia.org/wiki/NGC_6528 "NGC 6528") [6530](https://en.wikipedia.org/wiki/NGC_6530 "NGC 6530") [6540](https://en.wikipedia.org/wiki/NGC_6540 "NGC 6540") [6544](https://en.wikipedia.org/wiki/NGC_6544 "NGC 6544") [6553](https://en.wikipedia.org/wiki/NGC_6553 "NGC 6553") [6558](https://en.wikipedia.org/wiki/NGC_6558 "NGC 6558") [6569](https://en.wikipedia.org/wiki/NGC_6569 "NGC 6569") [6603](https://en.wikipedia.org/wiki/NGC_6603 "NGC 6603") [6624](https://en.wikipedia.org/wiki/NGC_6624 "NGC 6624") [6638](https://en.wikipedia.org/wiki/NGC_6638 "NGC 6638") [6642](https://en.wikipedia.org/wiki/NGC_6642 "NGC 6642") [6717](https://en.wikipedia.org/wiki/NGC_6717 "NGC 6717") [6723](https://en.wikipedia.org/wiki/NGC_6723 "NGC 6723") [6774](https://en.wikipedia.org/wiki/Ruprecht_147 "Ruprecht 147") | | Other | [1806−20 cluster](https://en.wikipedia.org/wiki/1806%E2%88%9220_cluster "1806−20 cluster") [2MASS-GC02](https://en.wikipedia.org/wiki/2MASS-GC02 "2MASS-GC02") [Arches Cluster](https://en.wikipedia.org/wiki/Arches_Cluster "Arches Cluster") [CO−0.40−0.22](https://en.wikipedia.org/wiki/CO%E2%88%920.40%E2%88%920.22 "CO−0.40−0.22") [Messier 18](https://en.wikipedia.org/wiki/Messier_18 "Messier 18") [Messier 21](https://en.wikipedia.org/wiki/Messier_21 "Messier 21") [Messier 22](https://en.wikipedia.org/wiki/Messier_22 "Messier 22") [Messier 23](https://en.wikipedia.org/wiki/Messier_23 "Messier 23") [Messier 25](https://en.wikipedia.org/wiki/Messier_25 "Messier 25") [Messier 28](https://en.wikipedia.org/wiki/Messier_28 "Messier 28") [Messier 54](https://en.wikipedia.org/wiki/Messier_54 "Messier 54") [Messier 55](https://en.wikipedia.org/wiki/Messier_55 "Messier 55") [Messier 69](https://en.wikipedia.org/wiki/Messier_69 "Messier 69") [Messier 70](https://en.wikipedia.org/wiki/Messier_70 "Messier 70") [Messier 75](https://en.wikipedia.org/wiki/Messier_75 "Messier 75") [Quintuplet Cluster](https://en.wikipedia.org/wiki/Quintuplet_Cluster "Quintuplet Cluster") [Small Sagittarius Star Cloud](https://en.wikipedia.org/wiki/Small_Sagittarius_Star_Cloud "Small Sagittarius Star Cloud") [Terzan 5](https://en.wikipedia.org/wiki/Terzan_5 "Terzan 5") [Terzan 7](https://en.wikipedia.org/wiki/Terzan_7 "Terzan 7") [Terzan 8](https://en.wikipedia.org/wiki/Terzan_8 "Terzan 8") [VVV CL001](https://en.wikipedia.org/wiki/VVV_CL001 "VVV CL001") | | [Nebulae](https://en.wikipedia.org/wiki/Nebula "Nebula") | | | | | | NGC | [6445](https://en.wikipedia.org/wiki/NGC_6445 "NGC 6445") [6559](https://en.wikipedia.org/wiki/NGC_6559 "NGC 6559") [6563](https://en.wikipedia.org/wiki/NGC_6563 "NGC 6563") [6565](https://en.wikipedia.org/wiki/NGC_6565 "NGC 6565") [6578](https://en.wikipedia.org/wiki/NGC_6578 "NGC 6578") [6589](https://en.wikipedia.org/wiki/NGC_6589 "NGC 6589") [6590](https://en.wikipedia.org/wiki/NGC_6590 "NGC 6590") [6629](https://en.wikipedia.org/wiki/NGC_6629 "NGC 6629") [6644](https://en.wikipedia.org/wiki/NGC_6644 "NGC 6644") [6818](https://en.wikipedia.org/wiki/NGC_6818 "NGC 6818") | | Other | [Barnard 92](https://en.wikipedia.org/wiki/Barnard_92 "Barnard 92") [Bubble Nebula in NGC 6822](https://en.wikipedia.org/wiki/Bubble_Nebula_\(NGC_6822\) "Bubble Nebula (NGC 6822)") [G1.9+0.3](https://en.wikipedia.org/wiki/G1.9%2B0.3 "G1.9+0.3") [HCN−0.009−0.044](https://en.wikipedia.org/wiki/HCN%E2%88%920.009%E2%88%920.044 "HCN−0.009−0.044") [Lagoon Nebula](https://en.wikipedia.org/wiki/Lagoon_Nebula "Lagoon Nebula") [Large Molecule Heimat](https://en.wikipedia.org/wiki/Large_Molecule_Heimat "Large Molecule Heimat") [M 1-42](https://en.wikipedia.org/wiki/M_1-42 "M 1-42") [M2-42](https://en.wikipedia.org/wiki/M2-42 "M2-42") [Omega Nebula](https://en.wikipedia.org/wiki/Omega_Nebula "Omega Nebula") [Pistol Nebula](https://en.wikipedia.org/wiki/Pistol_Nebula "Pistol Nebula") [RCW 136](https://en.wikipedia.org/wiki/RCW_136 "RCW 136") [RCW 145](https://en.wikipedia.org/wiki/RCW_145 "RCW 145") [Red Spider Nebula](https://en.wikipedia.org/wiki/Red_Spider_Nebula "Red Spider Nebula") [Ring Nebula in NGC 6822](https://en.wikipedia.org/wiki/Ring_Nebula_\(NGC_6822\) "Ring Nebula (NGC 6822)") [Sagittarius A](https://en.wikipedia.org/wiki/Sagittarius_A "Sagittarius A") [Sh 2-16](https://en.wikipedia.org/wiki/Sh_2-16 "Sh 2-16") [Sh 2-17](https://en.wikipedia.org/wiki/Sh_2-17 "Sh 2-17") [Sh 2-18](https://en.wikipedia.org/wiki/Sh_2-18 "Sh 2-18") [Sh 2-19](https://en.wikipedia.org/wiki/Sh_2-19 "Sh 2-19") [Sh 2-20](https://en.wikipedia.org/wiki/Sh_2-20 "Sh 2-20") [Sh 2-22](https://en.wikipedia.org/wiki/Sh_2-22 "Sh 2-22") [Sh 2-31](https://en.wikipedia.org/wiki/Sh_2-31 "Sh 2-31") [Sh 2-32](https://en.wikipedia.org/wiki/Sh_2-32 "Sh 2-32") [Sh 2-34](https://en.wikipedia.org/wiki/Sh_2-34 "Sh 2-34") [Sh 2-35](https://en.wikipedia.org/wiki/Sh_2-35 "Sh 2-35") [Sh 2-37](https://en.wikipedia.org/wiki/Sh_2-37 "Sh 2-37") [Sh 2-38](https://en.wikipedia.org/wiki/Sh_2-38 "Sh 2-38") [Sh 2-40](https://en.wikipedia.org/wiki/Sh_2-40 "Sh 2-40") [Sh 2-41](https://en.wikipedia.org/wiki/Sh_2-41 "Sh 2-41") [Sh 2-42](https://en.wikipedia.org/wiki/Sh_2-42 "Sh 2-42") [Sh 2-43](https://en.wikipedia.org/wiki/Sh_2-43 "Sh 2-43") [Sh 2-44](https://en.wikipedia.org/wiki/Sh_2-44 "Sh 2-44") [Trifid Nebula](https://en.wikipedia.org/wiki/Trifid_Nebula "Trifid Nebula") [Westerhout 31](https://en.wikipedia.org/wiki/Westerhout_31 "Westerhout 31") | | [Galaxies](https://en.wikipedia.org/wiki/Galaxy "Galaxy") | | | | | | NGC | [6822](https://en.wikipedia.org/wiki/NGC_6822 "NGC 6822") [6902](https://en.wikipedia.org/wiki/NGC_6902 "NGC 6902") | | Other | [ESO 593-8](https://en.wikipedia.org/wiki/ESO_593-8 "ESO 593-8") [MRC 2011−298](https://en.wikipedia.org/wiki/MRC_2011%E2%88%92298 "MRC 2011−298") [PKS 1830−211](https://en.wikipedia.org/wiki/PKS_1830%E2%88%92211 "PKS 1830−211") [PKS 2000−330](https://en.wikipedia.org/wiki/PKS_2000%E2%88%92330 "PKS 2000−330") [PKS 2004−447](https://en.wikipedia.org/wiki/PKS_2004%E2%88%92447 "PKS 2004−447") [Sagittarius Dwarf Irregular Galaxy](https://en.wikipedia.org/wiki/Sagittarius_Dwarf_Irregular_Galaxy "Sagittarius Dwarf Irregular Galaxy") [Sagittarius Dwarf Spheroidal Galaxy](https://en.wikipedia.org/wiki/Sagittarius_Dwarf_Spheroidal_Galaxy "Sagittarius Dwarf Spheroidal Galaxy") | | | | | [Astronomical events](https://en.wikipedia.org/wiki/Transient_astronomical_event "Transient astronomical event") | [GLEAM-X J162759.5−523504.3](https://en.wikipedia.org/wiki/GLEAM-X_J162759.5%E2%88%92523504.3 "GLEAM-X J162759.5−523504.3") [GRB 020813](https://en.wikipedia.org/wiki/GRB_020813 "GRB 020813") [SN 386](https://en.wikipedia.org/wiki/SN_386 "SN 386") | | ![](https://upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/20px-Symbol_category_class.svg.png) [Category](https://en.wikipedia.org/wiki/Category:Sagittarius_\(constellation\) "Category:Sagittarius (constellation)") | | [Portals](https://en.wikipedia.org/wiki/Wikipedia:Contents/Portals "Wikipedia:Contents/Portals"): - ![](https://upload.wikimedia.org/wikipedia/commons/thumb/0/00/Crab_Nebula.jpg/20px-Crab_Nebula.jpg) [Astronomy](https://en.wikipedia.org/wiki/Portal:Astronomy "Portal:Astronomy") - [![icon](https://upload.wikimedia.org/wikipedia/commons/thumb/6/6f/Stylised_atom_with_three_Bohr_model_orbits_and_stylised_nucleus.svg/20px-Stylised_atom_with_three_Bohr_model_orbits_and_stylised_nucleus.svg.png)](https://en.wikipedia.org/wiki/File:Stylised_atom_with_three_Bohr_model_orbits_and_stylised_nucleus.svg) [Physics](https://en.wikipedia.org/wiki/Portal:Physics "Portal:Physics") - [![icon](https://upload.wikimedia.org/wikipedia/commons/thumb/5/5f/He1523a.jpg/20px-He1523a.jpg)](https://en.wikipedia.org/wiki/File:He1523a.jpg) [Stars](https://en.wikipedia.org/wiki/Portal:Stars "Portal:Stars") - ![](https://upload.wikimedia.org/wikipedia/commons/thumb/5/5c/Earth-moon.jpg/40px-Earth-moon.jpg) [Outer space](https://en.wikipedia.org/wiki/Portal:Outer_space "Portal:Outer space") - [![icon](https://upload.wikimedia.org/wikipedia/commons/thumb/8/8b/Nuvola_apps_kalzium.svg/20px-Nuvola_apps_kalzium.svg.png)](https://en.wikipedia.org/wiki/File:Nuvola_apps_kalzium.svg) [Science](https://en.wikipedia.org/wiki/Portal:Science "Portal:Science") | [Authority control databases](https://en.wikipedia.org/wiki/Help:Authority_control "Help:Authority control") [![Edit this at Wikidata](https://upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/20px-OOjs_UI_icon_edit-ltr-progressive.svg.png)](https://www.wikidata.org/wiki/Q237284#identifiers "Edit this at Wikidata") | | |---|---| | International | [VIAF](https://viaf.org/viaf/316600730) [FAST](https://id.worldcat.org/fast/1922707) | | National | [United States](https://id.loc.gov/authorities/sh2007002976) [Israel](https://www.nli.org.il/en/authorities/987007556708205171) | ![](https://en.wikipedia.org/wiki/Special:CentralAutoLogin/start?useformat=desktop&type=1x1&usesul3=1) Retrieved from 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This article is about the black hole. For the surrounding region, see [Sagittarius A](https://en.wikipedia.org/wiki/Sagittarius_A "Sagittarius A"). | | | |---|---| | [![](https://upload.wikimedia.org/wikipedia/commons/thumb/9/96/EHT_Saggitarius_A_black_hole.tif/lossy-page1-250px-EHT_Saggitarius_A_black_hole.tif.jpg)](https://en.wikipedia.org/wiki/File:EHT_Saggitarius_A_black_hole.tif) Sagittarius A\* imaged by the [Event Horizon Telescope](https://en.wikipedia.org/wiki/Event_Horizon_Telescope "Event Horizon Telescope") in 2017, released in 2022 | | | Observation data [Epoch](https://en.wikipedia.org/wiki/Epoch_\(astronomy\) "Epoch (astronomy)") [J2000](https://en.wikipedia.org/wiki/J2000 "J2000") [Equinox](https://en.wikipedia.org/wiki/Equinox_\(celestial_coordinates\) "Equinox (celestial coordinates)") [J2000](https://en.wikipedia.org/wiki/J2000 "J2000") | | | [Constellation](https://en.wikipedia.org/wiki/Constellation "Constellation") | [Sagittarius](https://en.wikipedia.org/wiki/Sagittarius_\(constellation\) "Sagittarius (constellation)") | | [Right ascension](https://en.wikipedia.org/wiki/Right_ascension "Right ascension") | 17h 45m 40.0409s | | [Declination](https://en.wikipedia.org/wiki/Declination "Declination") | −29° 0â€Č 28.118″[\[1\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-1) | | Details | | | **[Mass](https://en.wikipedia.org/wiki/Stellar_mass "Stellar mass")** | 8\.54×1036 kg 4\.297×106[\[2\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-GRAVITY-2) [M☉](https://en.wikipedia.org/wiki/Solar_mass "Solar mass") | | [Astrometry](https://en.wikipedia.org/wiki/Astrometry "Astrometry") | | | **[Distance](https://en.wikipedia.org/wiki/Distance_\(astronomy\) "Distance (astronomy)")** | 26996±33[\[2\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-GRAVITY-2) [ly](https://en.wikipedia.org/wiki/Light-year "Light-year") (8277±9[\[2\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-GRAVITY-2) [pc](https://en.wikipedia.org/wiki/Parsec "Parsec")) | | Database references | | | **[SIMBAD](https://en.wikipedia.org/wiki/SIMBAD "SIMBAD")** | [data](https://simbad.cds.unistra.fr/simbad/sim-id?Ident=NAME+Sgr+A*) | **Sagittarius A\***, [abbreviated](https://en.wikipedia.org/wiki/Abbreviation "Abbreviation") as **Sgr A\*** ( [*SADGE\-AY\-star*](https://en.wikipedia.org/wiki/Help:Pronunciation_respelling_key "Help:Pronunciation respelling key")[\[3\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-3)), is the [supermassive black hole](https://en.wikipedia.org/wiki/Supermassive_black_hole "Supermassive black hole")[\[4\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-4)[\[5\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-5)[\[6\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-plait-6) at the [Galactic Center](https://en.wikipedia.org/wiki/Galactic_Center "Galactic Center") of the [Milky Way](https://en.wikipedia.org/wiki/Milky_Way "Milky Way"). Viewed from Earth, it is located near the border of the constellations [Sagittarius](https://en.wikipedia.org/wiki/Sagittarius_\(constellation\) "Sagittarius (constellation)") and [Scorpius](https://en.wikipedia.org/wiki/Scorpius "Scorpius"), about 5.6° south of the [ecliptic](https://en.wikipedia.org/wiki/Ecliptic "Ecliptic"),[\[7\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-7) visually close to the [Butterfly Cluster](https://en.wikipedia.org/wiki/Butterfly_Cluster "Butterfly Cluster") (M6) and [Lambda Scorpii](https://en.wikipedia.org/wiki/Lambda_Scorpii "Lambda Scorpii"). Sagittarius A\* is a bright and very compact [astronomical radio source](https://en.wikipedia.org/wiki/Astronomical_radio_source "Astronomical radio source"). In May 2022, astronomers released the first image of the [accretion disk](https://en.wikipedia.org/wiki/Accretion_disk "Accretion disk") around the event horizon of Sagittarius A\*,[\[8\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-8) using the [Event Horizon Telescope](https://en.wikipedia.org/wiki/Event_Horizon_Telescope "Event Horizon Telescope"), a world-wide network of radio observatories.[\[9\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-AJ-202205-9) This is the second confirmed image of a black hole, after [Messier 87's supermassive black hole](https://en.wikipedia.org/wiki/Messier_87#Supermassive_black_hole_M87* "Messier 87") in 2019.[\[10\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-ESO2208-10)[\[11\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-NYT-20220512-11) The black hole itself is not seen; as light is incapable of escaping the immense gravitational force of a black hole, only nearby objects whose behavior is influenced by the black hole can be observed. The observed radio and infrared energy emanates from gas and dust heated to millions of degrees while falling into the black hole.[\[12\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-DetectionOfBlackHoleSrgA-12) Sgr A\* was discovered in 1974 by [Bruce Balick](https://en.wikipedia.org/wiki/Bruce_Balick "Bruce Balick") and Robert L. Brown,[\[13\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Intense_sub-arcsecond_structure_in-13)[\[14\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Melia_2007,_p._7-14) and the [asterisk](https://en.wikipedia.org/wiki/Asterisk "Asterisk") **\*** was assigned in 1982 by Brown,[\[15\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-15) who understood that the strongest radio emission from the center of the galaxy appeared to be due to a compact non-thermal radio object embedded in a larger, and much brighter, radio source, [Sagittarius A](https://en.wikipedia.org/wiki/Sagittarius_A "Sagittarius A") (Sgr A). The observation of several stars orbiting Sagittarius A\*, particularly [star S2](https://en.wikipedia.org/wiki/S2_\(star\) "S2 (star)"), have been used to determine the mass and upper limits on the radius of the object. Based on the mass and the precise radius limits obtained, astronomers concluded that Sagittarius A\* was the central supermassive black hole of the Milky Way galaxy.[\[16\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Henderson-16) The current best estimate of its mass is 4.297±0\.012 million [solar masses](https://en.wikipedia.org/wiki/Solar_mass "Solar mass").[\[2\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-GRAVITY-2) [Reinhard Genzel](https://en.wikipedia.org/wiki/Reinhard_Genzel "Reinhard Genzel") and [Andrea Ghez](https://en.wikipedia.org/wiki/Andrea_M._Ghez "Andrea M. Ghez") were each awarded a quarter share in the 2020 [Nobel Prize in Physics](https://en.wikipedia.org/wiki/Nobel_Prize_in_Physics "Nobel Prize in Physics") for their discovery that Sagittarius A\* is a supermassive compact object, for which a [black hole](https://en.wikipedia.org/wiki/Black_hole "Black hole") was the only explanation. [Sir Roger Penrose](https://en.wikipedia.org/wiki/Roger_Penrose "Roger Penrose") received the other half "for the discovery that black hole formation is a robust prediction of the [general theory of relativity](https://en.wikipedia.org/wiki/General_theory_of_relativity "General theory of relativity")".[\[17\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-17) ## Observation and description \[[edit](https://en.wikipedia.org/w/index.php?title=Sagittarius_A*&action=edit&section=1 "Edit section: Observation and description")\] [![](https://upload.wikimedia.org/wikipedia/commons/thumb/e/e8/Sagittarius_Astar_in_the_constellation_of_Sagittarius.tif/lossy-page1-250px-Sagittarius_Astar_in_the_constellation_of_Sagittarius.tif.jpg)](https://en.wikipedia.org/wiki/File:Sagittarius_Astar_in_the_constellation_of_Sagittarius.tif) Sagittarius A\* in the constellation of Sagittarius. The black hole is marked with a red circle within the constellation of Sagittarius (The Archer). This map shows most of the stars visible to the unaided eye under good conditions. [![](https://upload.wikimedia.org/wikipedia/commons/thumb/e/e1/Eso2208-eht-mwe.tif/lossy-page1-250px-Eso2208-eht-mwe.tif.jpg)](https://en.wikipedia.org/wiki/File:Eso2208-eht-mwe.tif) Size comparison between Sagittarius A\* and [M87\*](https://en.wikipedia.org/wiki/Messier_87#Supermassive_black_hole_M87* "Messier 87"). The diameter of Sagittarius A\* is smaller than the orbit of [Mercury](https://en.wikipedia.org/wiki/Mercury_\(planet\) "Mercury (planet)"). On May 12, 2022, the first image of Sagittarius A\* was released by the [Event Horizon Telescope Collaboration](https://en.wikipedia.org/wiki/Event_Horizon_Telescope_Collaboration "Event Horizon Telescope Collaboration"). The image, which is based on radio interferometer data taken in 2017, confirms that the object contains a black hole. This is the second image of a black hole,[\[10\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-ESO2208-10)[\[18\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Shadow-18) and took five years of calculations to process.[\[19\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-19) The data were collected by eight radio observatories at six geographical sites. Radio images are produced from data by [aperture synthesis](https://en.wikipedia.org/wiki/Aperture_synthesis "Aperture synthesis"), usually from night-long observations of stable sources. The radio emission from Sgr A\* varies on the order of minutes, complicating the analysis.[\[20\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-20) Their result gives an overall [angular size](https://en.wikipedia.org/wiki/Angular_diameter "Angular diameter") for the source of 51\.8±2\.3 [ÎŒas](https://en.wikipedia.org/wiki/Microarcsecond "Microarcsecond").[\[18\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Shadow-18) At a distance of 26,000 [light-years](https://en.wikipedia.org/wiki/Light-year "Light-year") (8,000 [parsecs](https://en.wikipedia.org/wiki/Parsec "Parsec")), this yields a diameter of 51.8 million kilometres (32.2 million miles).[\[a\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-dc1-21) For comparison, Earth is 150 million [kilometres](https://en.wikipedia.org/wiki/Kilometre "Kilometre") (1.0 [astronomical unit](https://en.wikipedia.org/wiki/Astronomical_unit "Astronomical unit"); 93 million [miles](https://en.wikipedia.org/wiki/Mile "Mile")) from the [Sun](https://en.wikipedia.org/wiki/Sun "Sun"), and [Mercury](https://en.wikipedia.org/wiki/Mercury_\(planet\) "Mercury (planet)") is 46 million km (0.31 AU; 29 million mi) from the Sun at [perihelion](https://en.wikipedia.org/wiki/Apsis "Apsis"). The [proper motion](https://en.wikipedia.org/wiki/Proper_motion "Proper motion") of Sgr A\* is approximately −2.70 [mas](https://en.wikipedia.org/wiki/Minute_and_second_of_arc "Minute and second of arc") per year for the [right ascension](https://en.wikipedia.org/wiki/Right_ascension "Right ascension") and −5.6 mas per year for the [declination](https://en.wikipedia.org/wiki/Declination "Declination").[\[21\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-22)[\[22\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-23)[\[23\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-24) The telescope's measurement of these black holes tested Einstein's [theory of relativity](https://en.wikipedia.org/wiki/Theory_of_relativity "Theory of relativity") more rigorously than has previously been done, and the results match perfectly.[\[11\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-NYT-20220512-11) In 2019, measurements made with the High-resolution Airborne Wideband Camera-Plus (HAWC+) mounted in the [SOFIA](https://en.wikipedia.org/wiki/Stratospheric_Observatory_for_Infrared_Astronomy "Stratospheric Observatory for Infrared Astronomy") aircraft[\[24\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-25) revealed that magnetic fields cause the surrounding ring of gas and dust, temperatures of which range from −280 to 17,500 °F (99.8 to 9,977.6 K; −173.3 to 9,704.4 °C),[\[25\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-26) to flow into an orbit around Sagittarius A\*, keeping black hole emissions low.[\[26\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-27) Astronomers have been unable to observe Sgr A\* in the [Visible spectrum](https://en.wikipedia.org/wiki/Visible_spectrum "Visible spectrum") because of the effect of 25 [magnitudes](https://en.wikipedia.org/wiki/Magnitude_\(astronomy\) "Magnitude (astronomy)") of [extinction](https://en.wikipedia.org/wiki/Extinction_\(astronomy\) "Extinction (astronomy)") (absorption and scattering) by dust and gas between the source and Earth.[\[27\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Osterbrock-28) In April 1933, [Karl Jansky](https://en.wikipedia.org/wiki/Karl_Guthe_Jansky "Karl Guthe Jansky"), considered one of the fathers of radio astronomy, discovered that a radio signal was coming from a location in the direction of the constellation of Sagittarius, towards the center of the Milky Way.[\[28\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-29) The radio source later became known as [Sagittarius A](https://en.wikipedia.org/wiki/Sagittarius_A "Sagittarius A"). His observations did not extend quite as far south as we now know to be the Galactic Center.[\[29\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-goss_history-30) Observations by [Jack Piddington](https://en.wikipedia.org/wiki/Jack_Piddington "Jack Piddington") and [Harry Minnett](https://en.wikipedia.org/wiki/Harry_Clive_Minnett "Harry Clive Minnett") using the [CSIRO](https://en.wikipedia.org/wiki/CSIRO "CSIRO") radio telescope at [Potts Hill Reservoir](https://en.wikipedia.org/wiki/Potts_Hill_Reservoirs_1_and_2 "Potts Hill Reservoirs 1 and 2"), in [Sydney](https://en.wikipedia.org/wiki/Sydney "Sydney") discovered a discrete and bright "Sagittarius-Scorpius" radio source,[\[30\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-piddington-31) which after further observation with the 80-foot (24-metre) CSIRO radio telescope at [Dover Heights](https://en.wikipedia.org/wiki/Dover_Heights "Dover Heights") was identified in a letter to *[Nature](https://en.wikipedia.org/wiki/Nature_\(journal\) "Nature (journal)")* as the probable Galactic Center.[\[31\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-galactic_centre_mcgee-32) Later observations showed that Sagittarius A actually consists of several overlapping sub-components; a bright and very compact component, Sgr A\*, was discovered on February 13 and 15, 1974, by Balick and Robert L. Brown using the baseline interferometer of the [National Radio Astronomy Observatory](https://en.wikipedia.org/wiki/National_Radio_Astronomy_Observatory "National Radio Astronomy Observatory").[\[13\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Intense_sub-arcsecond_structure_in-13)[\[14\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Melia_2007,_p._7-14) The name Sgr A\* was coined by Brown in a 1982 paper because the radio source was "exciting", and [excited states](https://en.wikipedia.org/wiki/Excited_state "Excited state") of atoms are denoted with asterisks.[\[32\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-33)[\[33\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-34) Since the 1980s, it has been evident that the central component of Sgr A\* is likely a black hole. In 1994, infrared and sub-millimetre spectroscopy studies by a [Berkeley](https://en.wikipedia.org/wiki/University_of_California,_Berkeley "University of California, Berkeley") team involving [Nobel Laureate](https://en.wikipedia.org/wiki/Nobel_Prize_in_Physics "Nobel Prize in Physics") [Charles H. Townes](https://en.wikipedia.org/wiki/Charles_H._Townes "Charles H. Townes") and future Nobel Prize Winner [Reinhard Genzel](https://en.wikipedia.org/wiki/Reinhard_Genzel "Reinhard Genzel") showed that the mass of Sgr A\* was tightly concentrated and on the order of 3 million Suns.[\[34\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-35) On October 16, 2002, an international team led by [Reinhard Genzel](https://en.wikipedia.org/wiki/Reinhard_Genzel "Reinhard Genzel") at the [Max Planck Institute for Extraterrestrial Physics](https://en.wikipedia.org/wiki/Max_Planck_Institute_for_Extraterrestrial_Physics "Max Planck Institute for Extraterrestrial Physics") reported the observation of the motion of the star [S2](https://en.wikipedia.org/wiki/S2_\(star\) "S2 (star)") near Sagittarius A\* throughout a period of ten years. According to the team's analysis, the data ruled out the possibility that Sgr A\* contains a cluster of dark stellar objects or a mass of [degenerate fermions](https://en.wikipedia.org/wiki/Degenerate_matter "Degenerate matter"), strengthening the evidence for a massive black hole. The observations of S2 used [near-infrared](https://en.wikipedia.org/wiki/Near-infrared "Near-infrared") (NIR) [interferometry](https://en.wikipedia.org/wiki/Astronomical_interferometer "Astronomical interferometer") (in the Ks-band, i.e. 2.1 [ÎŒm](https://en.wikipedia.org/wiki/%CE%9Cm "Μm")) because of reduced [interstellar extinction](https://en.wikipedia.org/wiki/Extinction_\(astronomy\) "Extinction (astronomy)") in this band. SiO [masers](https://en.wikipedia.org/wiki/Astrophysical_maser "Astrophysical maser") were used to align NIR images with radio observations, as they can be observed in both NIR and radio bands. The rapid motion of S2 (and other nearby stars) easily stood out against slower-moving stars along the line-of-sight so these could be subtracted from the images.[\[35\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-36)[\[36\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-37) [![](https://upload.wikimedia.org/wikipedia/commons/thumb/6/6d/Dusty_cloud_G2_passes_the_supermassive_black_hole_at_the_centre_of_the_Milky_Way.jpg/330px-Dusty_cloud_G2_passes_the_supermassive_black_hole_at_the_centre_of_the_Milky_Way.jpg)](https://en.wikipedia.org/wiki/File:Dusty_cloud_G2_passes_the_supermassive_black_hole_at_the_centre_of_the_Milky_Way.jpg) Dusty cloud G2 passes the supermassive black hole at the center of the Milky Way.[\[37\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-38) Composition of images taken at different times to show motion; colored blue when approaching the viewer, red when receding; time is left to right. Red cross marks the black hole. The VLBI radio observations of Sagittarius A\* could also be aligned centrally with the NIR images, so the focus of S2's elliptical orbit was found to coincide with the position of Sagittarius A\*. From examining the [Keplerian orbit](https://en.wikipedia.org/wiki/Kepler_orbit "Kepler orbit") of S2, they determined the mass of Sagittarius A\* to be 4\.1±0\.6 million [solar masses](https://en.wikipedia.org/wiki/Solar_mass "Solar mass"), confined in a volume with a radius no more than 17 light-hours (120 [AU](https://en.wikipedia.org/wiki/Astronomical_unit "Astronomical unit") \[18 [billion](https://en.wikipedia.org/wiki/1000000000_\(number\) "1000000000 (number)") [km](https://en.wikipedia.org/wiki/Kilometre "Kilometre"); 11 billion [mi](https://en.wikipedia.org/wiki/Mile "Mile")\]).[\[38\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-39) Later observations of the star S14 showed the mass of the object to be about 4.1 million solar masses within a volume with radius no larger than 6.25 light-hours (45 AU \[6.7 billion km; 4.2 billion mi\]).[\[39\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Ghez08-40) S175 passed within a similar distance.[\[40\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-41) For comparison, the [Schwarzschild radius](https://en.wikipedia.org/wiki/Schwarzschild_radius "Schwarzschild radius") is 0.08 AU (12 million km; 7.4 million mi). They also determined the distance from Earth to the [Galactic Center](https://en.wikipedia.org/wiki/Galactic_Center "Galactic Center") (the rotational center of the Milky Way), which is important in calibrating astronomical distance scales, as 8,000 ± 600 [parsecs](https://en.wikipedia.org/wiki/Parsec "Parsec") (30,000 ± 2,000 [light-years](https://en.wikipedia.org/wiki/Light-year "Light-year")). In November 2004, a team of astronomers reported the discovery of a potential [intermediate-mass black hole](https://en.wikipedia.org/wiki/Intermediate-mass_black_hole "Intermediate-mass black hole"), referred to as [GCIRS 13E](https://en.wikipedia.org/wiki/GCIRS_13E "GCIRS 13E"), orbiting 3 light-years from Sagittarius A\*. This black hole of 1,300 solar masses is within a cluster of seven stars. This observation may add support to the idea that supermassive black holes grow by absorbing nearby smaller black holes and stars.\[*[citation needed](https://en.wikipedia.org/wiki/Wikipedia:Citation_needed "Wikipedia:Citation needed")*\] After monitoring stellar orbits around Sagittarius A\* for 16 years, Gillessen *et al.* estimated the object's mass at 4\.31±0\.38 million solar masses. The result was announced in 2008 and published in *[The Astrophysical Journal](https://en.wikipedia.org/wiki/The_Astrophysical_Journal "The Astrophysical Journal")* in 2009.[\[41\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Gillessen-42) [Reinhard Genzel](https://en.wikipedia.org/wiki/Reinhard_Genzel "Reinhard Genzel"), team leader of the research, said the study has delivered "what is now considered to be the best empirical evidence that supermassive black holes do really exist. The stellar orbits in the Galactic Center show that the central mass concentration of four million solar masses must be a black hole, beyond any reasonable doubt."[\[42\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-43) On January 5, 2015, NASA reported observing an [X-ray](https://en.wikipedia.org/wiki/X-ray "X-ray") flare 400 times brighter than usual, a record-breaker, from Sgr A\*. The unusual event may have been caused by the breaking apart of an [asteroid](https://en.wikipedia.org/wiki/Asteroid "Asteroid") falling into the black hole or by the entanglement of [magnetic field](https://en.wikipedia.org/wiki/Magnetic_field "Magnetic field") lines within gas flowing into Sgr A\*, according to astronomers.[\[43\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-NASA-20150105-44) On 13 May 2019, astronomers using the [Keck Observatory](https://en.wikipedia.org/wiki/Keck_Observatory "Keck Observatory") witnessed a sudden brightening of Sgr A\*, which became 75 times brighter than usual, suggesting that the supermassive black hole may have encountered another object.[\[44\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-45) In June 2023, unexplained filaments of [radio](https://en.wikipedia.org/wiki/Radio_wave "Radio wave") energy were found associated with Sagittarius A\*.[\[45\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-NYT-20230608-46) - [![ALMA observations of molecular-hydrogen-rich gas clouds, with the area around Sagittarius A\* circled\[46\]](https://upload.wikimedia.org/wikipedia/commons/thumb/a/ab/Cloudlets_swarm_around_our_local_supermassive_black_hole.tif/lossy-page1-250px-Cloudlets_swarm_around_our_local_supermassive_black_hole.tif.jpg)](https://en.wikipedia.org/wiki/File:Cloudlets_swarm_around_our_local_supermassive_black_hole.tif "ALMA observations of molecular-hydrogen-rich gas clouds, with the area around Sagittarius A* circled[46]") [ALMA](https://en.wikipedia.org/wiki/Atacama_Large_Millimeter_Array "Atacama Large Millimeter Array") observations of molecular-hydrogen-rich gas clouds, with the area around Sagittarius A\* circled[\[46\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-47) - [![An unusually bright X-ray flare from Sgr A\* was detected in 2013.\[43\]](https://upload.wikimedia.org/wikipedia/commons/thumb/8/85/X-RayFlare-BlackHole-MilkyWay-20140105.jpg/330px-X-RayFlare-BlackHole-MilkyWay-20140105.jpg)](https://en.wikipedia.org/wiki/File:X-RayFlare-BlackHole-MilkyWay-20140105.jpg "An unusually bright X-ray flare from Sgr A* was detected in 2013.[43]") An unusually bright [X-ray](https://en.wikipedia.org/wiki/X-ray "X-ray") flare from Sgr A\* was detected in 2013.[\[43\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-NASA-20150105-44) - [![Supernova remnant ejecta producing planet-forming material seen in radio and X-ray](https://upload.wikimedia.org/wikipedia/commons/thumb/1/19/15-044a-SuperNovaRemnant-PlanetFormation-SOFIA-20150319.jpg/330px-15-044a-SuperNovaRemnant-PlanetFormation-SOFIA-20150319.jpg)](https://en.wikipedia.org/wiki/File:15-044a-SuperNovaRemnant-PlanetFormation-SOFIA-20150319.jpg "Supernova remnant ejecta producing planet-forming material seen in radio and X-ray") [Supernova remnant](https://en.wikipedia.org/wiki/Supernova_remnant "Supernova remnant") ejecta producing planet-forming material seen in radio and X-ray - [![Supernova remnant ejecta producing planet-forming material seen in infrared and X-ray](https://upload.wikimedia.org/wikipedia/commons/thumb/0/01/15-044b-SuperNovaRemnant-PlanetFormation-SOFIA-20150319.jpg/330px-15-044b-SuperNovaRemnant-PlanetFormation-SOFIA-20150319.jpg)](https://en.wikipedia.org/wiki/File:15-044b-SuperNovaRemnant-PlanetFormation-SOFIA-20150319.jpg "Supernova remnant ejecta producing planet-forming material seen in infrared and X-ray") Supernova remnant ejecta producing planet-forming material seen in infrared and X-ray [![](https://upload.wikimedia.org/wikipedia/commons/thumb/6/63/Pointing_X-ray_Eyes_at_our_Resident_Supermassive_Black_Hole.jpg/330px-Pointing_X-ray_Eyes_at_our_Resident_Supermassive_Black_Hole.jpg)](https://en.wikipedia.org/wiki/File:Pointing_X-ray_Eyes_at_our_Resident_Supermassive_Black_Hole.jpg) [NuSTAR](https://en.wikipedia.org/wiki/NuSTAR "NuSTAR") has captured these first, focused views of the supermassive black hole at the heart of the Milky Way in high-energy X-rays. In a paper published on October 31, 2018, the discovery of conclusive evidence that Sagittarius A\* is a black hole was announced. Using the [GRAVITY](https://en.wikipedia.org/wiki/List_of_instruments_at_the_Very_Large_Telescope "List of instruments at the Very Large Telescope") [interferometer](https://en.wikipedia.org/wiki/Interferometry "Interferometry") and the four telescopes of the [Very Large Telescope](https://en.wikipedia.org/wiki/Very_Large_Telescope "Very Large Telescope") (VLT) to create a virtual telescope 130 metres (430 feet) in diameter, astronomers detected clumps of gas moving at about 30% of the speed of light. Emission from highly energetic electrons very close to the black hole was visible as three prominent bright flares. These exactly match theoretical predictions for hot spots orbiting close to a black hole of four million solar masses. The flares are thought to originate from magnetic interactions in the very hot gas orbiting very close to Sagittarius A\*.[\[12\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-DetectionOfBlackHoleSrgA-12)[\[47\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-ESO-48) In July 2018, it was reported that [S2](https://en.wikipedia.org/wiki/S2_\(star\) "S2 (star)") orbiting Sgr A\* had been recorded at 7,650 km/s (17.1 million mph), or 2.55% the [speed of light](https://en.wikipedia.org/wiki/Speed_of_light "Speed of light"), leading up to the [pericenter](https://en.wikipedia.org/wiki/Apsis#Terminology "Apsis") approach, in May 2018, at about 120 [AU](https://en.wikipedia.org/wiki/Astronomical_unit "Astronomical unit") (18 [billion](https://en.wikipedia.org/wiki/1000000000_\(number\) "1000000000 (number)") [km](https://en.wikipedia.org/wiki/Kilometre "Kilometre"); 11 billion [mi](https://en.wikipedia.org/wiki/Mile "Mile")) (approximately 1,400 [Schwarzschild radii](https://en.wikipedia.org/wiki/Schwarzschild_radius "Schwarzschild radius")) from Sgr A\*. At that close distance to the black hole, [Einstein](https://en.wikipedia.org/wiki/Albert_Einstein "Albert Einstein")'s theory of [general relativity](https://en.wikipedia.org/wiki/General_relativity "General relativity") predicts that S2 would show a discernible [gravitational redshift](https://en.wikipedia.org/wiki/Gravitational_redshift "Gravitational redshift") in addition to the usual velocity redshift. The gravitational redshift was detected, in agreement with the general relativity prediction within the 10 percent measurement precision.[\[48\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-aa33718-18-49)[\[49\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-2017-07-26_TG-50) The Sagittarius A\* radio emissions are not centered on the black hole, but arise from a bright spot in the region around the black hole, close to the [event horizon](https://en.wikipedia.org/wiki/Event_horizon "Event horizon"), possibly in the [accretion disc](https://en.wikipedia.org/wiki/Accretion_disk "Accretion disk"), or a [relativistic jet](https://en.wikipedia.org/wiki/Relativistic_jet "Relativistic jet") of material ejected from the disc.[\[50\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-EHS-51) If the apparent position of Sagittarius A\* were exactly centered on the black hole, it would be possible to see it magnified beyond its size, because of [gravitational lensing](https://en.wikipedia.org/wiki/Gravitational_lens "Gravitational lens") of the black hole. According to [general relativity](https://en.wikipedia.org/wiki/General_relativity "General relativity"), this would result in a ring-like structure, which has a diameter about 5.2 times the black hole's [Schwarzschild radius](https://en.wikipedia.org/wiki/Schwarzschild_radius "Schwarzschild radius") (10 ÎŒas). For a black hole of around 4 million solar masses, this corresponds to a size of approximately 52 [ÎŒas](https://en.wikipedia.org/wiki/%CE%9Cas "Μas"), which is consistent with the observed overall size of about 50 ÎŒas,[\[50\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-EHS-51) the size (apparent diameter) of the black hole Sgr A\* itself being 20 ÎŒas. Lower resolution observations revealed that the radio source of Sagittarius A\* is symmetrical.[\[51\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Issaoun-52) Simulations of alternative theories of gravity depict results that may be difficult to distinguish from GR.[\[52\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-53) A 2018 paper predicted an image of Sagittarius A\* that is in agreement with observations. In particular, it explains the small angular size and the symmetrical morphology of the source.[\[53\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-54) The mass of Sagittarius A\* has been estimated in two different ways: 1. Two groups—in Germany and the U.S.—monitored the orbits of individual stars very near to the black hole and used [Kepler's laws](https://en.wikipedia.org/wiki/Kepler%27s_laws "Kepler's laws") to infer the enclosed mass. The German group found a mass of 4\.31±0\.38 million solar masses,[\[41\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Gillessen-42) whereas the American group found 4\.1±0\.6 million solar masses.[\[39\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Ghez08-40) Given that this mass is confined inside a 44-million-kilometre-diameter sphere, this yields a density ten times higher than previous estimates.\[*[citation needed](https://en.wikipedia.org/wiki/Wikipedia:Citation_needed "Wikipedia:Citation needed")*\] 2. More recently, measurement of the [proper motions](https://en.wikipedia.org/wiki/Proper_motion "Proper motion") of a sample of several thousand stars within approximately one parsec from the black hole, combined with a [statistical technique](https://en.wikipedia.org/wiki/Leonard%E2%80%93Merritt_mass_estimator "Leonard–Merritt mass estimator"), has yielded both an estimate of the black hole's mass at 3\.6\+0.2 −0.4×106 M ☉, plus a distributed mass in the central parsec amounting to (1±0\.5)×106 M ☉.[\[54\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-55) The latter is thought to be composed of stars and [stellar remnants](https://en.wikipedia.org/wiki/Stellar_remnant "Stellar remnant").\[*[citation needed](https://en.wikipedia.org/wiki/Wikipedia:Citation_needed "Wikipedia:Citation needed")*\] [![](https://upload.wikimedia.org/wikipedia/commons/thumb/d/d3/Magnetar-SGR1745-2900-20150515.jpg/250px-Magnetar-SGR1745-2900-20150515.jpg)](https://en.wikipedia.org/wiki/File:Magnetar-SGR1745-2900-20150515.jpg) [Magnetar](https://en.wikipedia.org/wiki/Magnetar "Magnetar") found very close to the [supermassive black hole](https://en.wikipedia.org/wiki/Supermassive_black_hole "Supermassive black hole"), Sagittarius A\*, at the center of the Milky Way galaxy The comparatively small mass of this [supermassive black hole](https://en.wikipedia.org/wiki/Supermassive_black_hole "Supermassive black hole"), along with the low luminosity of the radio and infrared emission lines, imply that the Milky Way is not a [Seyfert galaxy](https://en.wikipedia.org/wiki/Seyfert_galaxy "Seyfert galaxy").[\[27\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Osterbrock-28) Ultimately, what is seen is not the black hole itself, but observations that are consistent only if there is a black hole present near Sgr A\*. In the case of such a black hole, the observed radio and infrared energy emanates from gas and dust heated to millions of degrees while falling into the black hole.[\[12\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-DetectionOfBlackHoleSrgA-12) The black hole itself is thought to emit only [Hawking radiation](https://en.wikipedia.org/wiki/Hawking_radiation "Hawking radiation") at a negligible temperature, on the order of 10−14 [kelvin](https://en.wikipedia.org/wiki/Kelvin "Kelvin").\[*[citation needed](https://en.wikipedia.org/wiki/Wikipedia:Citation_needed "Wikipedia:Citation needed")*\] The [European Space Agency](https://en.wikipedia.org/wiki/European_Space_Agency "European Space Agency")'s [gamma-ray](https://en.wikipedia.org/wiki/Gamma-ray "Gamma-ray") observatory [INTEGRAL](https://en.wikipedia.org/wiki/INTEGRAL "INTEGRAL") observed gamma rays interacting with the nearby [giant molecular cloud](https://en.wikipedia.org/wiki/Giant_molecular_cloud "Giant molecular cloud") [Sagittarius B2](https://en.wikipedia.org/wiki/Sagittarius_B2 "Sagittarius B2"), causing X-ray emission from the cloud. The total luminosity from this outburst (*L*≈1,5×1039 erg/s) is estimated to be a million times stronger than the current output from Sgr A\* and is comparable with a typical [active galactic nucleus](https://en.wikipedia.org/wiki/Active_galactic_nucleus "Active galactic nucleus").[\[55\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-hubble050127-56)[\[56\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-revnivtsev2004-57) In 2011 this conclusion was supported by Japanese astronomers observing the Milky Way's center with the *[Suzaku](https://en.wikipedia.org/wiki/Suzaku_\(satellite\) "Suzaku (satellite)")* satellite.[\[57\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-nobukawa2011-58) In July 2019, astronomers reported finding a star, [S5-HVS1](https://en.wikipedia.org/wiki/S5-HVS1 "S5-HVS1"), traveling 1,755 km/s (3.93 million mph) or 0.006 *c*. The star is in the [Grus](https://en.wikipedia.org/wiki/Grus_\(constellation\) "Grus (constellation)") (or Crane) [constellation](https://en.wikipedia.org/wiki/Constellation "Constellation") in the southern sky, and about 29,000 light-years from Earth, and may have been propelled out of the [Milky Way](https://en.wikipedia.org/wiki/Milky_Way "Milky Way") [galaxy](https://en.wikipedia.org/wiki/Galaxy "Galaxy") after interacting with Sagittarius A\*.[\[58\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-NYT-20191114-59)[\[59\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-MNRAS-20191109-60) Several values[\[60\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-61)[\[61\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-:02-62) have been given for its spin parameter ![{\\displaystyle a\_{\*}={\\frac {cJ}{GM^{2}}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/bb6b50a7a6320b77aa1016a31fed667855c0b718); some examples are Fragione & Loeb (2020) ![{\\displaystyle a\_{\*}\<0.1}](https://wikimedia.org/api/rest_v1/media/math/render/svg/5caea805df13ecdb0f468a13cfde9e3905da8cfa)[\[62\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-63)*,* Belanger et al. (2006) ![{\\displaystyle a\_{\*}\\sim 0.22}](https://wikimedia.org/api/rest_v1/media/math/render/svg/8a71eca52c51efd1d812a9e0dd80d8d0e0fcf3fb),[\[63\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-64) Meyer et al. (2006) ![{\\displaystyle a\_{\*}\>0.4}](https://wikimedia.org/api/rest_v1/media/math/render/svg/970a4fff5d1decb07b2da845307f62c8bee1d1b1),[\[64\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-65) Genzel et al. (2003) ![{\\displaystyle a\_{\*}\\sim 0.52}](https://wikimedia.org/api/rest_v1/media/math/render/svg/d0d7e4e45719dc21a120dbe45ab34674383ecf22),[\[65\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-66) Daly (2019) ![{\\displaystyle a\_{\*}=0.93\\pm 0.15}](https://wikimedia.org/api/rest_v1/media/math/render/svg/3f6e61ddba8f03442b71e56298129d5dcd7c9398),[\[66\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-67) and Daly et al. (2023) ![{\\displaystyle a\_{\*}=0.90\\pm 0.06}](https://wikimedia.org/api/rest_v1/media/math/render/svg/1ac7981d75faf23ee39294d909158d66a263acbe).[\[61\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-:02-62) Daly et al. (2023) also found that the ratio of the black hole rotational mass component to the irreducible mass component of Sgr A\* is ![{\\displaystyle M\_{rot}/M\_{irr}=0.62\\pm 0.10}](https://wikimedia.org/api/rest_v1/media/math/render/svg/ebd5eb15903976409fa2d2f6f063bbda02ff1382), which indicates that the black hole is rotating with an angular velocity that is ![{\\displaystyle 0.62\\pm 0.10}](https://wikimedia.org/api/rest_v1/media/math/render/svg/5eadf14e64dec9c59ba8238d0bc162bd55324385) of the maximum possible value, set by the speed of light.[\[61\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-:02-62) [\[67\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-:03-68) [![](https://upload.wikimedia.org/wikipedia/commons/thumb/c/c1/Galactic_centre_orbits.svg/250px-Galactic_centre_orbits.svg.png)](https://en.wikipedia.org/wiki/File:Galactic_centre_orbits.svg) Inferred orbits of six stars around supermassive black hole candidate Sagittarius A\* at the Milky Way's center[\[68\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Eisenhauer-69) [![](https://upload.wikimedia.org/wikipedia/commons/thumb/5/50/SgrA2018.gif/250px-SgrA2018.gif)](https://en.wikipedia.org/wiki/File:SgrA2018.gif) Stars moving around Sagittarius A\*, 20-year timelapse, ending in 2018[\[69\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-70)[\[70\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-:0-71) [![](https://upload.wikimedia.org/wikipedia/commons/thumb/c/c4/SgrA2021.gif/250px-SgrA2021.gif)](https://en.wikipedia.org/wiki/File:SgrA2021.gif) Stars moving around Sagittarius A\* as seen in 2021[\[71\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-72)[\[72\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-73)[\[73\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-74) There are a number of stars in close orbit around Sagittarius A\*, which are collectively known as "S stars".[\[74\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-75) These stars are observed primarily in [K band](https://en.wikipedia.org/wiki/K_band_\(infrared\) "K band (infrared)") infrared wavelengths, as interstellar dust drastically limits visibility in visible wavelengths. This is a rapidly changing field—in 2011, the orbits of the most prominent stars then known were plotted in the diagram at left, showing a comparison between their orbits and various orbits in the [Solar System](https://en.wikipedia.org/wiki/Solar_System "Solar System").[\[70\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-:0-71) Since then, [S62](https://en.wikipedia.org/wiki/S62_\(star\) "S62 (star)") was thought to approach even more closely than those stars,[\[75\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-apj-76) but later observations of the star have found this not to be the case.[\[76\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-p994-77) The high velocities and close approaches to the supermassive black hole makes these stars useful to establish limits on the physical dimensions of Sagittarius A\*, as well as to observe general relativity associated effects like periapse shift of their orbits. An active watch is maintained for the possibility of stars approaching the event horizon close enough to be disrupted, but none of these stars are expected to suffer that fate. As of 2020, S4714 is the current record holder of closest approach to Sagittarius A\*, at about 12.6 AU (1.88 billion km), almost as close as Saturn gets to the Sun, traveling at about 8% of the speed of light. These figures given are approximate, the formal uncertainties being 12\.6±9\.3 AU and 23,928±8,840 km/s. Its orbital period is 12 years, but an extreme eccentricity of 0.985 gives it the close approach and high velocity.[\[77\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-78) An excerpt from a table of this cluster (see [Sagittarius A\* cluster](https://en.wikipedia.org/wiki/Sagittarius_A*_cluster "Sagittarius A* cluster")), featuring the most prominent members. In the below table, **id1** is the star's name in the Gillessen catalog and **id2** in the catalog of the University of California, Los Angeles. **a**, **e**, **i**, **Ω** and **ω** are standard [orbital elements](https://en.wikipedia.org/wiki/Orbital_elements "Orbital elements"), with **a** measured in [arcseconds](https://en.wikipedia.org/wiki/Arcsecond "Arcsecond"). **Tp** is the epoch of pericenter passage, **P** is the orbital period in years and **Kmag** is the infrared [K-band](https://en.wikipedia.org/wiki/K_band_\(infrared\) "K band (infrared)") [apparent magnitude](https://en.wikipedia.org/wiki/Apparent_magnitude "Apparent magnitude") of the star. **q** and **v** are the pericenter distance in [AU](https://en.wikipedia.org/wiki/Astronomical_unit "Astronomical unit") and pericenter speed in percent of the [speed of light](https://en.wikipedia.org/wiki/Speed_of_light "Speed of light").[\[78\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-naess-79) | id1 | id2 | a | e | i (°) | Ω (°) | ω (°) | Tp (yr) | P (yr) | Kmag | q (AU) | v (%c) | |---|---|---|---|---|---|---|---|---|---|---|---| | S1 | S0-1 | 0\.5950 | 0\.5560 | 119\.14 | 342\.04 | 122\.30 | 2001\.800 | 166\.0 | 14\.70 | 2160\.7 | 0\.55 | | [S2](https://en.wikipedia.org/wiki/S2_\(star\) "S2 (star)") | S0-2 | 0\.1251 | 0\.8843 | 133\.91 | 228\.07 | 66\.25 | 2018\.379 | 16\.1 | 13\.95 | 118\.4 | 2\.56 | | S8 | S0-4 | 0\.4047 | 0\.8031 | 74\.37 | 315\.43 | 346\.70 | 1983\.640 | 92\.9 | 14\.50 | 651\.7 | 1\.07 | | S12 | S0-19 | 0\.2987 | 0\.8883 | 33\.56 | 230\.10 | 317\.90 | 1995\.590 | 58\.9 | 15\.50 | 272\.9 | 1\.69 | | S13 | S0-20 | 0\.2641 | 0\.4250 | 24\.70 | 74\.50 | 245\.20 | 2004\.860 | 49\.0 | 15\.80 | 1242\.0 | 0\.69 | | S14 | S0-16 | 0\.2863 | 0\.9761 | 100\.59 | 226\.38 | 334\.59 | 2000\.120 | 55\.3 | 15\.70 | 56\.0 | 3\.83 | | S4714 | | 0\.102 | 0\.985 | 127\.7 | 129\.28 | 357\.25 | 2017\.29 | 12\.0 | 17\.7 | 12\.6 | 8\.0 | ## Discovery of G2 gas cloud on an accretion course \[[edit](https://en.wikipedia.org/w/index.php?title=Sagittarius_A*&action=edit&section=5 "Edit section: Discovery of G2 gas cloud on an accretion course")\] First noticed as something unusual in images of the center of the Milky Way in 2002,[\[79\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Matson-80) the gas cloud G2, which has a mass about three times that of Earth, was confirmed to be likely on a course taking it into the accretion zone of Sgr A\* in a paper published in *Nature* in 2012.[\[80\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Gillessen_2012_51%E2%80%9354-81) Predictions of its orbit suggested it would make its closest approach to the black hole (a [perinigricon](https://en.wikipedia.org/wiki/Apsis "Apsis")) in early 2014, when the cloud was at a distance of just over 3,000 times the radius of the event horizon (or ≈260 AU, 36 light-hours) from the black hole. G2 has been observed to be disrupting since 2009,[\[80\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Gillessen_2012_51%E2%80%9354-81) and was predicted by some to be completely destroyed by the encounter, which could have led to a significant brightening of X-ray and other emission from the black hole. Other astronomers suggested the gas cloud could be hiding a dim star, or a binary star merger product, which would hold it together against the tidal forces of Sgr A\*, allowing the ensemble to pass by without any effect.[\[81\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Witzel2014-82) In addition to the tidal effects on the cloud itself, it was proposed in May 2013[\[82\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Bartos-83) that, prior to its perinigricon, G2 might experience multiple close encounters with members of the black-hole and neutron-star populations thought to orbit near the Galactic Center, offering some insight to the region surrounding the supermassive black hole at the center of the Milky Way.[\[83\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Geometry-84) The average rate of accretion onto Sgr A\* is unusually small for a black hole of its mass[\[84\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-85) and is only detectable because it is so close to Earth. It was thought that the passage of G2 in 2013 might offer astronomers the chance to learn much more about how material accretes onto supermassive black holes. Several astronomical facilities observed this closest approach, with observations confirmed with [Chandra](https://en.wikipedia.org/wiki/Chandra_X-ray_Observatory "Chandra X-ray Observatory"), [XMM](https://en.wikipedia.org/wiki/XMM-Newton "XMM-Newton"), [VLA](https://en.wikipedia.org/wiki/Very_Large_Array "Very Large Array"), [INTEGRAL](https://en.wikipedia.org/wiki/INTEGRAL "INTEGRAL"), [Swift](https://en.wikipedia.org/wiki/Neil_Gehrels_Swift_Observatory "Neil Gehrels Swift Observatory"), [Fermi](https://en.wikipedia.org/wiki/Fermi_Gamma-ray_Space_Telescope "Fermi Gamma-ray Space Telescope") and requested at [VLT](https://en.wikipedia.org/wiki/Very_Large_Telescope "Very Large Telescope") and [Keck](https://en.wikipedia.org/wiki/W._M._Keck_Observatory "W. M. Keck Observatory").[\[85\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-86) Simulations of the passage were made before it happened by groups at [ESO](https://en.wikipedia.org/wiki/European_Southern_Observatory "European Southern Observatory")[\[86\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-87) and [Lawrence Livermore National Laboratory](https://en.wikipedia.org/wiki/Lawrence_Livermore_National_Laboratory "Lawrence Livermore National Laboratory") (LLNL).[\[87\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-88) As the cloud approached the black hole, [Daryl Haggard](https://en.wikipedia.org/wiki/Daryl_Haggard "Daryl Haggard") said, "It's exciting to have something that feels more like an experiment", and hoped that the interaction would produce effects that would provide new information and insights.[\[88\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-89) Nothing was observed during and after the closest approach of the cloud to the black hole, which was described as a lack of "fireworks" and a "flop".[\[89\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-nature140721-90) Astronomers from the UCLA Galactic Center Group published observations obtained on March 19 and 20, 2014, concluding that G2 was still intact (in contrast to predictions for a simple gas cloud hypothesis) and that the cloud was likely to have a central star.[\[81\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Witzel2014-82) An analysis published on July 21, 2014, based on observations by the [ESO](https://en.wikipedia.org/wiki/European_Southern_Observatory "European Southern Observatory")'s [Very Large Telescope](https://en.wikipedia.org/wiki/Very_Large_Telescope "Very Large Telescope") in Chile, concluded alternatively that the cloud, rather than being isolated, might be a dense clump within a continuous but thinner stream of matter, and would act as a constant breeze on the disk of matter orbiting the black hole, rather than sudden gusts that would have caused high brightness as they hit, as originally expected. Supporting this hypothesis, G1, a cloud that passed near the black hole 13 years ago, had an orbit almost identical to G2, consistent with both clouds, and a gas tail thought to be trailing G2, all being denser clumps within a large single gas stream.[\[89\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-nature140721-90)[\[90\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-91) [Andrea Ghez](https://en.wikipedia.org/wiki/Andrea_M._Ghez "Andrea M. Ghez") et al. suggested in 2014 that G2 is not a gas cloud but rather a pair of binary stars that had been orbiting the black hole in tandem and merged into an extremely large star.[\[81\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-Witzel2014-82)[\[91\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-92) [![](https://upload.wikimedia.org/wikipedia/commons/thumb/3/33/A_simulation_of_how_a_gas_cloud_that_has_been_observed_approaching_the_supermassive_black_hole_at_the_centre_of_the_galaxy.jpg/250px-A_simulation_of_how_a_gas_cloud_that_has_been_observed_approaching_the_supermassive_black_hole_at_the_centre_of_the_galaxy.jpg)](https://en.wikipedia.org/wiki/File:A_simulation_of_how_a_gas_cloud_that_has_been_observed_approaching_the_supermassive_black_hole_at_the_centre_of_the_galaxy.jpg) Artist impression of the accretion of gas cloud G2 onto Sgr A\*. Credit: ESO[\[92\]](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_note-93) This simulation shows a gas cloud, discovered in 2011, as it passes close to the supermassive black hole at the center of the Milky Way. This video sequence shows the motion of the dusty cloud G2 as it closes in on, and then passes, the supermassive black hole at the center of the Milky Way. - [Galactic Center GeV excess](https://en.wikipedia.org/wiki/Galactic_Center_GeV_excess "Galactic Center GeV excess") – Unexplained gamma rays from the Galactic Center - [List of nearest known black holes](https://en.wikipedia.org/wiki/List_of_nearest_known_black_holes "List of nearest known black holes") - [M87\*](https://en.wikipedia.org/wiki/Messier_87#Supermassive_black_hole_M87* "Messier 87") 1. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-dc1_21-0)** This roughly equates to around 37 times the diameter of the Sun at ~1,400,000 kilometers (~865,000 miles). 1. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-1)** [Reid and Brunthaler 2004](https://en.wikipedia.org/wiki/Sagittarius_A*#Reid) 2. ^ [***a***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-GRAVITY_2-0) [***b***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-GRAVITY_2-1) [***c***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-GRAVITY_2-2) [***d***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-GRAVITY_2-3) The GRAVITY collaboration (September 2023). ["Polarimetry and astrometry of NIR flares as event horizon scale, dynamical probes for the mass of Sgr A\*"](https://www.aanda.org/articles/aa/full_html/2023/09/aa47416-23/aa47416-23.html). *Astronomy & Astrophysics*. **677**: L10. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[2307\.11821](https://arxiv.org/abs/2307.11821). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2023A\&A...677L..10G](https://ui.adsabs.harvard.edu/abs/2023A&A...677L..10G). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1051/0004-6361/202347416](https://doi.org/10.1051%2F0004-6361%2F202347416). 3. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-3)** ["Astronomers reveal first image of the black hole at the heart of our galaxy"](https://eventhorizontelescope.org/blog/astronomers-reveal-first-image-black-hole-heart-our-galaxy). *Event Horizon Telescope*. May 12, 2022. [Archived](https://web.archive.org/web/20220512132514/https://eventhorizontelescope.org/blog/astronomers-reveal-first-image-black-hole-heart-our-galaxy) from the original on May 12, 2022. Retrieved May 12, 2022. 4. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-4)** Parsons, Jeff (October 31, 2018). ["Scientists find proof a supermassive black hole is lurking at the centre of the Milky Way"](https://metro.co.uk/2018/10/31/scientists-find-proof-a-supermassive-black-hole-is-lurking-at-the-centre-of-the-milky-way-8092994/). *Metro*. [Archived](https://web.archive.org/web/20181031214911/https://metro.co.uk/2018/10/31/scientists-find-proof-a-supermassive-black-hole-is-lurking-at-the-centre-of-the-milky-way-8092994/) from the original on October 31, 2018. Retrieved October 31, 2018. 5. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-5)** Mosher, Dave (October 31, 2018). ["A 'mind-boggling' telescope observation has revealed the point of no return for our galaxy's monster black hole"](https://web.archive.org/web/20181031144008/https://www.middletownpress.com/technology/businessinsider/article/Supermassive-black-holes-gorge-themselves-on-a-7971243.php). *The Middletown Press*. Business Insider. Archived from [the original](https://www.middletownpress.com/technology/businessinsider/article/Supermassive-black-holes-gorge-themselves-on-a-7971243.php) on October 31, 2018. Retrieved May 16, 2022. 6. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-plait_6-0)** [Plait, Phil](https://en.wikipedia.org/wiki/Phil_Plait "Phil Plait") (November 7, 2018). ["Astronomers See Material Orbiting a Black Hole \*Right\* at the Edge of Forever"](https://www.syfy.com/syfywire/astronomers-see-material-orbiting-a-black-hole-right-at-the-edge-of-forever). *Bad Astronomy*. Syfy Wire. [Archived](https://web.archive.org/web/20181110143143/https://www.syfy.com/syfywire/astronomers-see-material-orbiting-a-black-hole-right-at-the-edge-of-forever) from the original on November 10, 2018. Retrieved November 12, 2018. 7. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-7)** Calculated using [Equatorial and Ecliptic Coordinates](https://frostydrew.org/utilities.dc/convert/tool-eq_coordinates/pss-fdo/) [Archived](https://web.archive.org/web/20190721134008/https://frostydrew.org/utilities.dc/convert/tool-eq_coordinates/pss-fdo/) July 21, 2019, at the [Wayback Machine](https://en.wikipedia.org/wiki/Wayback_Machine "Wayback Machine") calculator 8. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-8)** Sutter, Paul (May 20, 2022). ["How did astronomers take a picture of our galaxy's supermassive black hole?"](https://www.astronomy.com/science/how-did-astronomers-take-a-picture-of-our-galaxys-supermassive-black-hole/). *Astronomy Magazine*. Retrieved April 16, 2025. "The Event Horizon Telescope (EHT) collaboration released the first ever image of the accretion disk around the Milky Way's supermassive black hole, Sagittarius A\* (Sgr A\*), on May 12, 2022." 9. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-AJ-202205_9-0)** Bower, Geoffrey C. (May 2022). ["Focus on First Sgr A\* Results from the Event Horizon Telescope"](https://iopscience.iop.org/journal/2041-8205/page/Focus_on_First_Sgr_A_Results). *[The Astrophysical Journal](https://en.wikipedia.org/wiki/The_Astrophysical_Journal "The Astrophysical Journal")*. [Archived](https://web.archive.org/web/20220719162915/https://iopscience.iop.org/journal/2041-8205/page/Focus_on_First_Sgr_A_Results) from the original on July 19, 2022. Retrieved May 12, 2022. 10. ^ [***a***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-ESO2208_10-0) [***b***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-ESO2208_10-1) ["Astronomers reveal first image of the black hole at the heart of our galaxy"](https://www.eso.org/public/news/eso2208-eht-mw/). *eso.org*. May 12, 2022. [Archived](https://web.archive.org/web/20220512130910/https://www.eso.org/public/news/eso2208-eht-mw/) from the original on May 12, 2022. Retrieved May 12, 2022. 11. ^ [***a***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-NYT-20220512_11-0) [***b***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-NYT-20220512_11-1) Overbye, Dennis (May 12, 2022). ["The Milky Way's Black Hole Comes to Light"](https://www.nytimes.com/2022/05/12/science/black-hole-photo.html). *[The New York Times](https://en.wikipedia.org/wiki/The_New_York_Times "The New York Times")*. [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0362-4331](https://search.worldcat.org/issn/0362-4331). [Archived](https://web.archive.org/web/20220512040455/https://www.nytimes.com/2022/05/12/science/black-hole-photo.html/) from the original on May 12, 2022. Retrieved May 12, 2022. 12. ^ [***a***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-DetectionOfBlackHoleSrgA_12-0) [***b***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-DetectionOfBlackHoleSrgA_12-1) [***c***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-DetectionOfBlackHoleSrgA_12-2) Abuter, R.; Amorim, A.; Bauböck, M.; Berger, J. P.; Bonnet, H.; Brandner, W.; ClĂ©net, Y.; CoudĂ© Du Foresto, V.; De Zeeuw, P. T.; Deen, C.; Dexter, J.; Duvert, G.; Eckart, A.; Eisenhauer, F.; [Förster Schreiber, N. M.](https://en.wikipedia.org/wiki/Natascha_F%C3%B6rster_Schreiber "Natascha Förster Schreiber"); Garcia, P.; Gao, F.; Gendron, E.; Genzel, R.; Gillessen, S.; Guajardo, P.; Habibi, M.; Haubois, X.; Henning, T.; Hippler, S.; Horrobin, M.; Huber, A.; JimĂ©nez Rosales, A.; Jocou, L.; et al. (2018). "Detection of orbital motions near the last stable circular orbit of the massive black hole SgrA". *Astronomy & Astrophysics*. **618**: L10. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[1810\.12641](https://arxiv.org/abs/1810.12641). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2018A\&A...618L..10G](https://ui.adsabs.harvard.edu/abs/2018A&A...618L..10G). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1051/0004-6361/201834294](https://doi.org/10.1051%2F0004-6361%2F201834294). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [53613305](https://api.semanticscholar.org/CorpusID:53613305). 13. ^ [***a***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Intense_sub-arcsecond_structure_in_13-0) [***b***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Intense_sub-arcsecond_structure_in_13-1) Balick, B.; Brown, R. L. (December 1, 1974). ["Intense sub-arcsecond structure in the galactic center"](https://doi.org/10.1086%2F153242). *Astrophysical Journal*. **194** (1): 265–270\. [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[1974ApJ...194..265B](https://ui.adsabs.harvard.edu/abs/1974ApJ...194..265B). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1086/153242](https://doi.org/10.1086%2F153242). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [121802758](https://api.semanticscholar.org/CorpusID:121802758). 14. ^ [***a***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Melia_2007,_p._7_14-0) [***b***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Melia_2007,_p._7_14-1) [Melia 2007](https://en.wikipedia.org/wiki/Sagittarius_A*#Melia), p. 7 15. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-15)** Brown, Robert L. (November 1, 1982). ["Precessing Jets in Sagittarius A: Gas Dynamics in the Central Parsec of the Galaxy"](https://doi.org/10.1086%2F160401). *The Astrophysical Journal*. **262**: 110–119\. [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[1982ApJ...262..110B](https://ui.adsabs.harvard.edu/abs/1982ApJ...262..110B). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1086/160401](https://doi.org/10.1086%2F160401). 16. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Henderson_16-0)** Henderson, Mark (December 9, 2009). ["Astronomers confirm black hole at the heart of the Milky Way"](https://web.archive.org/web/20081216235509/http://www.timesonline.co.uk/tol/news/uk/science/article5316001.ece). Times Online. Archived from [the original](http://www.timesonline.co.uk/tol/news/uk/science/article5316001.ece) on December 16, 2008. Retrieved June 6, 2019. 17. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-17)** ["The Nobel Prize in Physics 2020"](https://www.nobelprize.org/prizes/physics/2020/summary/). October 6, 2020. [Archived](https://web.archive.org/web/20210424115309/https://www.nobelprize.org/prizes/physics/2020/summary/) from the original on April 24, 2021. Retrieved October 7, 2020. 18. ^ [***a***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Shadow_18-0) [***b***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Shadow_18-1) The Event Horizon Telescope Collaboration (May 1, 2022). ["First Sagittarius A\* Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole in the Center of the Milky Way"](https://doi.org/10.3847%2F2041-8213%2Fac6674). *The Astrophysical Journal Letters*. **930** (2): L12. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[2311\.08680](https://arxiv.org/abs/2311.08680). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2022ApJ...930L..12E](https://ui.adsabs.harvard.edu/abs/2022ApJ...930L..12E). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.3847/2041-8213/ac6674](https://doi.org/10.3847%2F2041-8213%2Fac6674). [eISSN](https://en.wikipedia.org/wiki/EISSN_\(identifier\) "EISSN (identifier)") [2041-8213](https://search.worldcat.org/issn/2041-8213). [hdl](https://en.wikipedia.org/wiki/Hdl_\(identifier\) "Hdl (identifier)"):[10261/278882](https://hdl.handle.net/10261%2F278882). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [2041-8205](https://search.worldcat.org/issn/2041-8205). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [248744791](https://api.semanticscholar.org/CorpusID:248744791). 19. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-19)** Hensley, Kerry (May 12, 2022). ["First Image of the Milky Way's Supermassive Black Hole"](https://aasnova.org/2022/05/12/first-image-of-the-milky-ways-supermassive-black-hole/). *AAS Nova*. [Archived](https://web.archive.org/web/20220802102347/https://aasnova.org/2022/05/12/first-image-of-the-milky-ways-supermassive-black-hole/) from the original on August 2, 2022. Retrieved May 13, 2022. 20. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-20)** The Event Horizon Telescope Collaboration (May 1, 2022). ["First Sagittarius A\* Event Horizon Telescope Results. III. Imaging of the Galactic Center Supermassive Black Hole"](https://doi.org/10.3847%2F2041-8213%2Fac6429). *The Astrophysical Journal Letters*. **930** (2): L14. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[2311\.09479](https://arxiv.org/abs/2311.09479). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2022ApJ...930L..14E](https://ui.adsabs.harvard.edu/abs/2022ApJ...930L..14E). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.3847/2041-8213/ac6429](https://doi.org/10.3847%2F2041-8213%2Fac6429). [eISSN](https://en.wikipedia.org/wiki/EISSN_\(identifier\) "EISSN (identifier)") [2041-8213](https://search.worldcat.org/issn/2041-8213). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [2041-8205](https://search.worldcat.org/issn/2041-8205). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [248744704](https://api.semanticscholar.org/CorpusID:248744704). 21. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-22)** [Backer and Sramek 1999](https://en.wikipedia.org/wiki/Sagittarius_A*#Backer), § 3 22. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-23)** ["Focus on the First Event Horizon Telescope Results – The Astrophysical Journal Letters – IOPscience"](https://iopscience.iop.org/journal/2041-8205/page/Focus_on_EHT). *iopscience.iop.org*. [Archived](https://web.archive.org/web/20190514171744/https://iopscience.iop.org/journal/2041-8205/page/Focus_on_EHT) from the original on May 14, 2019. Retrieved April 10, 2019. 23. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-24)** Overbye, Dennis (April 10, 2019). ["Black Hole Picture Revealed for the First Time"](https://www.nytimes.com/2019/04/10/science/black-hole-picture.html). *The New York Times*. [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0362-4331](https://search.worldcat.org/issn/0362-4331). [Archived](https://web.archive.org/web/20190521020231/https://www.nytimes.com/2019/04/10/science/black-hole-picture.html) from the original on May 21, 2019. Retrieved April 10, 2019. 24. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-25)** ["HAWC+, the Far-Infrared Camera and Polarimeter for SOFIA"](https://www.sofia.usra.edu/science/instruments/hawc). 2018. [Archived](https://web.archive.org/web/20210803210336/https://www.sofia.usra.edu/science/instruments/hawc) from the original on August 3, 2021. Retrieved August 3, 2021. 25. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-26)** ["The Milky Way's Monster Black Hole Has a Cool Gas Halo – Literally"](https://www.space.com/milky-way-monster-black-hole-cool-disk.html). *Space.com*. June 5, 2019. [Archived](https://web.archive.org/web/20190619004814/https://www.space.com/milky-way-monster-black-hole-cool-disk.html) from the original on June 19, 2019. Retrieved June 19, 2019. 26. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-27)** ["Magnetic Fields May Muzzle Milky Way's Monster Black Hole"](https://www.space.com/milky-way-supermassive-black-hole-magnetic-field-quiet.html). *Space.com*. June 14, 2019. [Archived](https://web.archive.org/web/20190618050808/https://www.space.com/milky-way-supermassive-black-hole-magnetic-field-quiet.html) from the original on June 18, 2019. Retrieved June 19, 2019. 27. ^ [***a***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Osterbrock_28-0) [***b***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Osterbrock_28-1) [Osterbrock and Ferland 2006](https://en.wikipedia.org/wiki/Sagittarius_A*#Osterbrock), p. 390 28. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-29)** ["Karl Jansky: The Father of Radio Astronomy"](https://armaghplanet.com/karl-jansky-the-father-of-radio-astronomy.html). August 29, 2012. [Archived](https://web.archive.org/web/20190628163259/http://www.armaghplanet.com/karl-jansky-the-father-of-radio-astronomy.html) from the original on June 28, 2019. Retrieved January 27, 2019. 29. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-goss_history_30-0)** Goss, W. M.; McGee, R. X. (1996). ["The Discovery of the Radio Source Sagittarius A (Sgr A)"](https://ui.adsabs.harvard.edu/abs/1996ASPC..102..369G/abstract). *The Galactic Center, Astronomical Society of the Pacific Conference Series*. **102**: 369. [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[1996ASPC..102..369G](https://ui.adsabs.harvard.edu/abs/1996ASPC..102..369G). [Archived](https://web.archive.org/web/20210303171739/https://ui.adsabs.harvard.edu/abs/1996ASPC..102..369G/abstract) from the original on March 3, 2021. Retrieved February 25, 2021. 30. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-piddington_31-0)** Piddington, J. H.; Minnett, H. C. (December 1, 1951). ["Observations of Galactic Radiation at Frequencies of 1200 and 3000 Mc/s"](https://ui.adsabs.harvard.edu/abs/1951AuSRA...4..459P/abstract). *Australian Journal of Scientific Research A*. **4** (4): 459. [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[1951AuSRA...4..459P](https://ui.adsabs.harvard.edu/abs/1951AuSRA...4..459P). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1071/CH9510459](https://doi.org/10.1071%2FCH9510459). [Archived](https://web.archive.org/web/20210413090955/https://ui.adsabs.harvard.edu/abs/1951AuSRA...4..459P/abstract) from the original on April 13, 2021. Retrieved February 25, 2021. 31. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-galactic_centre_mcgee_32-0)** McGee, R. X.; Bolton, J. G. (May 1, 1954). ["Probable observation of the galactic nucleus at 400 Mc./s"](https://ui.adsabs.harvard.edu/abs/1954Natur.173..985M/abstract). *Nature*. **173** (4412): 985–987\. [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[1954Natur.173..985M](https://ui.adsabs.harvard.edu/abs/1954Natur.173..985M). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1038/173985b0](https://doi.org/10.1038%2F173985b0). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0028-0836](https://search.worldcat.org/issn/0028-0836). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [4188235](https://api.semanticscholar.org/CorpusID:4188235). [Archived](https://web.archive.org/web/20220130113909/https://ui.adsabs.harvard.edu/abs/1954Natur.173..985M/abstract) from the original on January 30, 2022. Retrieved February 25, 2021. 32. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-33)** Goss, W. M.; Brown, Robert L.; Lo, K. Y. (May 6, 2003). "The Discovery of Sgr A\*". *Astronomische Nachrichten*. **324** (1): 497. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[astro-ph/0305074](https://arxiv.org/abs/astro-ph/0305074). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2003ANS...324..497G](https://ui.adsabs.harvard.edu/abs/2003ANS...324..497G). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1002/asna.200385047](https://doi.org/10.1002%2Fasna.200385047). 33. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-34)** Brown, R. L. (November 1, 1982). ["Precessing jets in Sagittarius A – Gas dynamics in the central parsec of the galaxy"](https://doi.org/10.1086%2F160401). *Astrophysical Journal, Part 1*. **262**: 110–119\. [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[1982ApJ...262..110B](https://ui.adsabs.harvard.edu/abs/1982ApJ...262..110B). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1086/160401](https://doi.org/10.1086%2F160401). 34. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-35)** Genzel, R; Hollenbach, D; Townes, C H (1994). "The nucleus of our Galaxy". *Reports on Progress in Physics*. **57** (5): 417–479\. [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[1994RPPh...57..417G](https://ui.adsabs.harvard.edu/abs/1994RPPh...57..417G). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1088/0034-4885/57/5/001](https://doi.org/10.1088%2F0034-4885%2F57%2F5%2F001). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0034-4885](https://search.worldcat.org/issn/0034-4885). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [250900662](https://api.semanticscholar.org/CorpusID:250900662). 35. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-36)** [Schödel *et al.* 2002](https://en.wikipedia.org/wiki/Sagittarius_A*#Schodel) 36. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-37)** Sakai, Shoko; Lu, Jessica R.; Ghez, Andrea; Jia, Siyao; Do, Tuan; Witzel, Gunther; Gautam, Abhimat K.; Hees, Aurelien; Becklin, E.; Matthews, K.; Hosek, M. W. (March 5, 2019). ["The Galactic Center: An Improved Astrometric Reference Frame for Stellar Orbits around the Supermassive Black Hole"](https://doi.org/10.3847%2F1538-4357%2Fab0361). *The Astrophysical Journal*. **873** (1): 65. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[1901\.08685](https://arxiv.org/abs/1901.08685). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2019ApJ...873...65S](https://ui.adsabs.harvard.edu/abs/2019ApJ...873...65S). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.3847/1538-4357/ab0361](https://doi.org/10.3847%2F1538-4357%2Fab0361). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [1538-4357](https://search.worldcat.org/issn/1538-4357). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [119331998](https://api.semanticscholar.org/CorpusID:119331998). 37. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-38)** ["Best View Yet of Dusty Cloud Passing Galactic Centre Black Hole"](http://www.eso.org/public/news/eso1512/). [Archived](https://web.archive.org/web/20150407034121/http://www.eso.org/public/news/eso1512/) from the original on April 7, 2015. Retrieved June 16, 2015. 38. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-39)** [Ghez *et al.* (2003) "The First Measurement of Spectral Lines in a Short-Period Star Bound to the Galaxy's Central Black Hole: A Paradox of Youth" Astrophysical Journal **586** L127](https://en.wikipedia.org/wiki/Sagittarius_A*#Ghez03) 39. ^ [***a***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Ghez08_40-0) [***b***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Ghez08_40-1) Ghez, A. M.; et al. (December 2008). "Measuring Distance and Properties of the Milky Way's Central Supermassive Black Hole with Stellar Orbits". *Astrophysical Journal*. **689** (2): 1044–1062\. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[0808\.2870](https://arxiv.org/abs/0808.2870). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2008ApJ...689.1044G](https://ui.adsabs.harvard.edu/abs/2008ApJ...689.1044G). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1086/592738](https://doi.org/10.1086%2F592738). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [18335611](https://api.semanticscholar.org/CorpusID:18335611). 40. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-41)** Gillessen, S.; Plewa, P. M.; Eisenhauer, F.; Sari, R.; Waisberg, I.; Habibi, M.; Pfuhl, O.; George, E.; Dexter, J. (2017). ["An Update on Monitoring Stellar Orbits in the Galactic Center"](https://doi.org/10.3847%2F1538-4357%2Faa5c41). *The Astrophysical Journal*. **837** (1): 30. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[1611\.09144](https://arxiv.org/abs/1611.09144). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2017ApJ...837...30G](https://ui.adsabs.harvard.edu/abs/2017ApJ...837...30G). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.3847/1538-4357/aa5c41](https://doi.org/10.3847%2F1538-4357%2Faa5c41). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0004-637X](https://search.worldcat.org/issn/0004-637X). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [119087402](https://api.semanticscholar.org/CorpusID:119087402). 41. ^ [***a***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Gillessen_42-0) [***b***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Gillessen_42-1) [Gillessen *et al.* 2009](https://en.wikipedia.org/wiki/Sagittarius_A*#Gillessen) 42. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-43)** [O'Neill 2008](https://en.wikipedia.org/wiki/Sagittarius_A*#ONeill) 43. ^ [***a***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-NASA-20150105_44-0) [***b***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-NASA-20150105_44-1) Chou, Felicia; Anderson, Janet; Watzke, Megan (January 5, 2015). ["NASA's Chandra Detects Record-Breaking Outburst from Milky Way's Black Hole"](https://www.nasa.gov/press/2015/january/nasa-s-chandra-detects-record-breaking-outburst-from-milky-way-s-black-hole/). [NASA](https://en.wikipedia.org/wiki/NASA "NASA"). [Archived](https://web.archive.org/web/20150106100532/http://www.nasa.gov/press/2015/january/nasa-s-chandra-detects-record-breaking-outburst-from-milky-way-s-black-hole/) from the original on January 6, 2015. Retrieved January 6, 2015. 44. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-45)** ["Our Galaxy's Supermassive Black Hole Has Emitted a Mysteriously Bright Flare"](https://www.sciencealert.com/our-galaxy-s-supermassive-black-hole-just-mysteriously-got-really-really-bright). *Science Alert*. August 12, 2019. [Archived](https://web.archive.org/web/20190812120201/https://www.sciencealert.com/our-galaxy-s-supermassive-black-hole-just-mysteriously-got-really-really-bright) from the original on August 12, 2019. Retrieved August 12, 2019. 45. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-NYT-20230608_46-0)** [Overbye, Dennis](https://en.wikipedia.org/wiki/Dennis_Overbye "Dennis Overbye") (June 8, 2023). ["Our Local Black Hole Serves Up an 'Awe Moment' – Filaments of radio energy from Sagittarius A\*, the black hole at the center of the Milky Way galaxy, are turning astronomers' heads"](https://www.nytimes.com/2023/06/08/science/astronomy-cosmos-black-hole.html). *[The New York Times](https://en.wikipedia.org/wiki/The_New_York_Times "The New York Times")*. Retrieved June 9, 2023. `{{cite news}}`: CS1 maint: deprecated archival service ([link](https://en.wikipedia.org/wiki/Category:CS1_maint:_deprecated_archival_service "Category:CS1 maint: deprecated archival service")) 46. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-47)** ["Cloudlets swarm around our local supermassive black hole"](https://www.eso.org/public/images/potw1843a/). *www.eso.org*. [Archived](https://web.archive.org/web/20181022093902/https://www.eso.org/public/images/potw1843a/) from the original on October 22, 2018. Retrieved October 22, 2018. 47. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-ESO_48-0)** ["Most Detailed Observations of Material Orbiting close to a Black Hole"](https://www.eso.org/public/news/eso1835/). *European Southern Observatory (ESO)*. [Archived](https://web.archive.org/web/20181101000741/https://www.eso.org/public/news/eso1835/) from the original on November 1, 2018. Retrieved November 1, 2018. 48. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-aa33718-18_49-0)** Genzel; et al. (July 26, 2018). ["Detection of the gravitational redshift in the orbit of the star S2 near the Galactic centre massive black hole"](https://www.aanda.org/articles/aa/full_html/2018/07/aa33718-18/aa33718-18.html). *Astronomy & Astrophysics*. **615**: L15. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[1807\.09409](https://arxiv.org/abs/1807.09409). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2018A\&A...615L..15G](https://ui.adsabs.harvard.edu/abs/2018A&A...615L..15G). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1051/0004-6361/201833718](https://doi.org/10.1051%2F0004-6361%2F201833718). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [118891445](https://api.semanticscholar.org/CorpusID:118891445). [Archived](https://web.archive.org/web/20190404120522/https://www.aanda.org/articles/aa/full_html/2018/07/aa33718-18/aa33718-18.html) from the original on April 4, 2019. Retrieved July 27, 2018. 49. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-2017-07-26_TG_50-0)** ["Star spotted speeding near black hole at centre of Milky Way – Chile's Very Large Telescope tracks S2 star as it reaches mind-boggling speeds by supermassive black hole"](https://www.theguardian.com/science/2018/jul/26/star-spotted-speeding-near-milky-way-black-hole-for-first-time). *The Guardian*. July 26, 2017. [Archived](https://web.archive.org/web/20190404100253/https://www.theguardian.com/science/2018/jul/26/star-spotted-speeding-near-milky-way-black-hole-for-first-time) from the original on April 4, 2019. Retrieved July 27, 2018. 50. ^ [***a***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-EHS_51-0) [***b***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-EHS_51-1) Lu, R.; et al. (2018). ["Detection of intrinsic source structure at ~3 Schwarzschild radii with Millimeter-VLBI observations of Sgr A\*"](https://doi.org/10.3847%2F1538-4357%2Faabe2e). *Astrophysical Journal*. **859** (1): 60. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[1805\.09223](https://arxiv.org/abs/1805.09223). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.3847/1538-4357/aabe2e](https://doi.org/10.3847%2F1538-4357%2Faabe2e). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [51917277](https://api.semanticscholar.org/CorpusID:51917277). 51. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Issaoun_52-0)** Issaoun, S. (January 18, 2019). ["The Size, Shape, and Scattering of Sagittarius A\* at 86 GHz: First VLBI with ALMA"](https://doi.org/10.3847%2F1538-4357%2Faaf732). *The Astrophysical Journal*. **871** (1): 30. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[1901\.06226](https://arxiv.org/abs/1901.06226). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2019ApJ...871...30I](https://ui.adsabs.harvard.edu/abs/2019ApJ...871...30I). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.3847/1538-4357/aaf732](https://doi.org/10.3847%2F1538-4357%2Faaf732). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [84180473](https://api.semanticscholar.org/CorpusID:84180473). 52. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-53)** Rezzolla, Luciano (April 17, 2018). ["Astrophysicists Test Theories of Gravity with Black Hole Shadows"](https://scitechdaily.com/astrophysicists-test-theories-of-gravity-with-black-hole-shadows/). *SciTech Daily*. [Archived](https://web.archive.org/web/20190402072150/https://scitechdaily.com/astrophysicists-test-theories-of-gravity-with-black-hole-shadows/) from the original on April 2, 2019. Retrieved April 2, 2019. 53. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-54)** ["Revealing the black hole at the heart of the galaxy"](https://www.phys.org/news/2019-01-revealing-black-hole-heart-galaxy.html). Netherlands Research School for Astronomy. January 22, 2019. [Archived](https://web.archive.org/web/20190318132949/https://phys.org/news/2019-01-revealing-black-hole-heart-galaxy.html) from the original on March 18, 2019. Retrieved April 2, 2019 – via [Phys.org](https://en.wikipedia.org/wiki/Phys.org "Phys.org"). 54. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-55)** [Schödel *et al.* 2009](https://en.wikipedia.org/wiki/Sagittarius_A*#Schodel2) 55. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-hubble050127_56-0)** ["Integral rolls back history of Milky Way's super-massive black hole"](http://www.esa.int/SPECIALS/Integral/SEMSKPO3E4E_0.html). Hubble News Desk. January 28, 2005. [Archived](https://web.archive.org/web/20121016202343/http://www.esa.int/SPECIALS/Integral/SEMSKPO3E4E_0.html) from the original on October 16, 2012. Retrieved October 31, 2007. 56. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-revnivtsev2004_57-0)** Revnivtsev, M. G.; et al. (October 2004). "Hard X-ray view of the past activity of Sgr A\$^{\\star}\$ in a natural Compton mirror". *[Astronomy & Astrophysics](https://en.wikipedia.org/wiki/Astronomy_%26_Astrophysics "Astronomy & Astrophysics")*. **425** (3): L49–L52. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[astro-ph/0408190](https://arxiv.org/abs/astro-ph/0408190). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2004A\&A...425L..49R](https://ui.adsabs.harvard.edu/abs/2004A&A...425L..49R). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1051/0004-6361:200400064](https://doi.org/10.1051%2F0004-6361%3A200400064). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0004-6361](https://search.worldcat.org/issn/0004-6361). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [18872302](https://api.semanticscholar.org/CorpusID:18872302). 57. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-nobukawa2011_58-0)** Nobukawa, M.; et al. (September 8, 2011). "New Evidence for High Activity of the Supermassive Black Hole in our Galaxy". *[The Astrophysical Journal](https://en.wikipedia.org/wiki/The_Astrophysical_Journal "The Astrophysical Journal")*. **739** (2): L52. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[1109\.1950](https://arxiv.org/abs/1109.1950). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2011ApJ...739L..52N](https://ui.adsabs.harvard.edu/abs/2011ApJ...739L..52N). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1088/2041-8205/739/2/L52](https://doi.org/10.1088%2F2041-8205%2F739%2F2%2FL52). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [2041-8205](https://search.worldcat.org/issn/2041-8205). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [119244398](https://api.semanticscholar.org/CorpusID:119244398). 58. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-NYT-20191114_59-0)** [Overbye, Dennis](https://en.wikipedia.org/wiki/Dennis_Overbye "Dennis Overbye") (November 14, 2019). ["A Black Hole Threw a Star Out of the Milky Way Galaxy – So long, S5-HVS1, we hardly knew you"](https://www.nytimes.com/2019/11/14/science/stars-black-hole-milky-way.html). *[The New York Times](https://en.wikipedia.org/wiki/The_New_York_Times "The New York Times")*. [Archived](https://web.archive.org/web/20191117223906/https://www.nytimes.com/2019/11/14/science/stars-black-hole-milky-way.html) from the original on November 17, 2019. Retrieved November 18, 2019. 59. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-MNRAS-20191109_60-0)** Koposov, Sergey E; et al. (January 11, 2020). ["Discovery of a nearby 1700 km s−1 star ejected from the Milky Way by Sgr A\*"](https://doi.org/10.1093%2Fmnras%2Fstz3081). *[Monthly Notices of the Royal Astronomical Society](https://en.wikipedia.org/wiki/Monthly_Notices_of_the_Royal_Astronomical_Society "Monthly Notices of the Royal Astronomical Society")*. **491** (2): 2465–2480\. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[1907\.11725](https://arxiv.org/abs/1907.11725). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1093/mnras/stz3081](https://doi.org/10.1093%2Fmnras%2Fstz3081). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0035-8711](https://search.worldcat.org/issn/0035-8711). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [198968336](https://api.semanticscholar.org/CorpusID:198968336). 60. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-61)** Eckart, Andreas; Tursunov, A.A.; Zajacek, M.; Parsa, M.; Hosseini, E.; Subroweit, M.; Peissker, F.; Straubmeier, C.; Horrobin, M.; Karas, V. (February 1, 2019). ["Mass, Distance, Spin, Charge, and Orientation of the super massive black hole SgrA\*"](https://pos.sissa.it/342/048). *Proceedings of Science*. **342**. Sissa Medialab: 048. [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.22323/1.342.0048](https://doi.org/10.22323%2F1.342.0048). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [189921901](https://api.semanticscholar.org/CorpusID:189921901). 61. ^ [***a***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-:02_62-0) [***b***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-:02_62-1) [***c***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-:02_62-2) Daly, Ruth A; Donahue, Megan; O'Dea, Christopher P; Sebastian, Biny; Haggard, Daryl; Lu, Anan (October 28, 2023). ["New black hole spin values for Sagittarius A\* obtained with the outflow method"](https://academic.oup.com/mnras/article/527/1/428/7326786). *Monthly Notices of the Royal Astronomical Society*. **527** (1): 428–436\. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[2310\.12108](https://arxiv.org/abs/2310.12108). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1093/mnras/stad3228](https://doi.org/10.1093%2Fmnras%2Fstad3228). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0035-8711](https://search.worldcat.org/issn/0035-8711). 62. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-63)** Fragione, Giacomo; Loeb, Abraham (October 1, 2020). ["An Upper Limit on the Spin of SgrA\* Based on Stellar Orbits in Its Vicinity"](https://doi.org/10.3847%2F2041-8213%2Fabb9b4). *The Astrophysical Journal*. **901** (2): L32. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[2008\.11734](https://arxiv.org/abs/2008.11734). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2020ApJ...901L..32F](https://ui.adsabs.harvard.edu/abs/2020ApJ...901L..32F). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.3847/2041-8213/abb9b4](https://doi.org/10.3847%2F2041-8213%2Fabb9b4). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [2041-8213](https://search.worldcat.org/issn/2041-8213). 63. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-64)** BĂ©langer, G; Terrier, R; Jager, O C de; Goldwurm, A; Melia, F (December 1, 2006). ["Periodic Modulations in an X-ray Flare from Sagittarius A\*"](https://iopscience.iop.org/article/10.1088/1742-6596/54/1/066). *Journal of Physics: Conference Series*. **54**: 420–426\. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[astro-ph/0604337](https://arxiv.org/abs/astro-ph/0604337). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2006JPhCS..54..420B](https://ui.adsabs.harvard.edu/abs/2006JPhCS..54..420B). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1088/1742-6596/54/1/066](https://doi.org/10.1088%2F1742-6596%2F54%2F1%2F066). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [1742-6588](https://search.worldcat.org/issn/1742-6588). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [250670477](https://api.semanticscholar.org/CorpusID:250670477). 64. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-65)** Meyer, L.; Eckart, A.; Schödel, R.; Duschl, W. J.; MuĆŸić, K.; Dovčiak, M.; Karas, V. (December 2006). ["Near-infrared polarimetry setting constraints on the orbiting spot model for Sgr A\* flares"](http://www.aanda.org/10.1051/0004-6361:20065925). *Astronomy & Astrophysics*. **460** (1): 15–21\. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[astro-ph/0610104](https://arxiv.org/abs/astro-ph/0610104). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2006A\&A...460...15M](https://ui.adsabs.harvard.edu/abs/2006A&A...460...15M). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1051/0004-6361:20065925](https://doi.org/10.1051%2F0004-6361%3A20065925). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0004-6361](https://search.worldcat.org/issn/0004-6361). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [15370123](https://api.semanticscholar.org/CorpusID:15370123). 65. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-66)** Genzel, R.; Schödel, R.; Ott, T.; Eckart, A.; Alexander, T.; Lacombe, F.; Rouan, D.; Aschenbach, B. (November 2003). ["Near-infrared flares from accreting gas around the supermassive black hole at the Galactic Centre"](https://www.nature.com/articles/nature02065). *Nature*. **425** (6961): 934–937\. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[astro-ph/0310821](https://arxiv.org/abs/astro-ph/0310821). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2003Natur.425..934G](https://ui.adsabs.harvard.edu/abs/2003Natur.425..934G). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1038/nature02065](https://doi.org/10.1038%2Fnature02065). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0028-0836](https://search.worldcat.org/issn/0028-0836). [PMID](https://en.wikipedia.org/wiki/PMID_\(identifier\) "PMID (identifier)") [14586462](https://pubmed.ncbi.nlm.nih.gov/14586462). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [4325930](https://api.semanticscholar.org/CorpusID:4325930). 66. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-67)** Daly, Ruth A. (November 15, 2019). ["Black Hole Spin and Accretion Disk Magnetic Field Strength Estimates for More Than 750 Active Galactic Nuclei and Multiple Galactic Black Holes"](https://doi.org/10.3847%2F1538-4357%2Fab35e6). *The Astrophysical Journal*. **886** (1): 37. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[1905\.11319](https://arxiv.org/abs/1905.11319). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2019ApJ...886...37D](https://ui.adsabs.harvard.edu/abs/2019ApJ...886...37D). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.3847/1538-4357/ab35e6](https://doi.org/10.3847%2F1538-4357%2Fab35e6). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0004-637X](https://search.worldcat.org/issn/0004-637X). 67. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-:03_68-0)** Daly, Ruth A (October 20, 2022). ["Robust supermassive black hole spin mass-energy characteristics: a new method and results"](https://academic.oup.com/mnras/article/517/4/5144/6764739). *Monthly Notices of the Royal Astronomical Society*. **517** (4): 5144–5159\. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[2210\.07779](https://arxiv.org/abs/2210.07779). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1093/mnras/stac2976](https://doi.org/10.1093%2Fmnras%2Fstac2976). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0035-8711](https://search.worldcat.org/issn/0035-8711). 68. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Eisenhauer_69-0)** Eisenhauer, F.; et al. (July 20, 2005). "SINFONI in the Galactic Center: Young Stars and Infrared Flares in the Central Light-Month". *The Astrophysical Journal*. **628** (1): 246–259\. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[astro-ph/0502129](https://arxiv.org/abs/astro-ph/0502129). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2005ApJ...628..246E](https://ui.adsabs.harvard.edu/abs/2005ApJ...628..246E). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1086/430667](https://doi.org/10.1086%2F430667). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [122485461](https://api.semanticscholar.org/CorpusID:122485461). 69. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-70)** ["First Successful Test of Einstein's General Relativity Near Supermassive Black Hole – Culmination of 26 years of ESO observations of the heart of the Milky Way"](https://www.eso.org/public/news/eso1825/). *www.eso.org*. [Archived](https://web.archive.org/web/20190308114840/https://www.eso.org/public/news/eso1825/) from the original on March 8, 2019. Retrieved December 15, 2021. 70. ^ [***a***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-:0_71-0) [***b***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-:0_71-1) GRAVITY Collaboration; Abuter, R.; Amorim, A.; Anugu, N.; Bauböck, M.; Benisty, M.; Berger, J. P.; Blind, N.; Bonnet, H.; Brandner, W.; Buron, A. (July 2018). ["Detection of the gravitational redshift in the orbit of the star S2 near the Galactic centre massive black hole"](https://www.aanda.org/10.1051/0004-6361/201833718). *Astronomy & Astrophysics*. **615**: L15. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[1807\.09409](https://arxiv.org/abs/1807.09409). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2018A\&A...615L..15G](https://ui.adsabs.harvard.edu/abs/2018A&A...615L..15G). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1051/0004-6361/201833718](https://doi.org/10.1051%2F0004-6361%2F201833718). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0004-6361](https://search.worldcat.org/issn/0004-6361). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [118891445](https://api.semanticscholar.org/CorpusID:118891445). [Archived](https://web.archive.org/web/20200727101247/https://www.aanda.org/10.1051/0004-6361/201833718) from the original on July 27, 2020. Retrieved December 15, 2021. 71. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-72)** ["Watch stars move around the Milky Way's supermassive black hole in deepest images yet"](https://www.eso.org/public/news/eso2119/). *www.eso.org*. [Archived](https://web.archive.org/web/20211214172128/https://www.eso.org/public/news/eso2119/) from the original on December 14, 2021. Retrieved December 15, 2021. 72. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-73)** GRAVITY Collaboration; Stadler, J.; Drescher, A. (December 14, 2021). ["Deep images of the Galactic center with GRAVITY"](https://doi.org/10.1051%2F0004-6361%2F202142459). *Astronomy & Astrophysics*. **657**: A82. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[2112\.07477](https://arxiv.org/abs/2112.07477). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1051/0004-6361/202142459](https://doi.org/10.1051%2F0004-6361%2F202142459). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0004-6361](https://search.worldcat.org/issn/0004-6361). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [245131155](https://api.semanticscholar.org/CorpusID:245131155). 73. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-74)** GRAVITY Collaboration; Abuter, R.; Aimar, N.; Amorim, A.; Ball, J.; Bauböck, M.; Gillessen, S.; Widmann, F.; Heissel, G. (December 14, 2021). ["Mass distribution in the Galactic Center based on interferometric astrometry of multiple stellar orbits"](https://doi.org/10.1051%2F0004-6361%2F202142465). *Astronomy & Astrophysics*. **657**: L12. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[2112\.07478](https://arxiv.org/abs/2112.07478). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1051/0004-6361/202142465](https://doi.org/10.1051%2F0004-6361%2F202142465). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0004-6361](https://search.worldcat.org/issn/0004-6361). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [245131377](https://api.semanticscholar.org/CorpusID:245131377). 74. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-75)** Eckart, A.; Genzel, R.; Ott, T.; Schödel, R. (April 11, 2002). ["Stellar orbits near Sagittarius A\*"](https://doi.org/10.1046%2Fj.1365-8711.2002.05237.x). *Monthly Notices of the Royal Astronomical Society*. **331** (4): 917–934\. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[astro-ph/0201031](https://arxiv.org/abs/astro-ph/0201031). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2002MNRAS.331..917E](https://ui.adsabs.harvard.edu/abs/2002MNRAS.331..917E). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1046/j.1365-8711.2002.05237.x](https://doi.org/10.1046%2Fj.1365-8711.2002.05237.x). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0035-8711](https://search.worldcat.org/issn/0035-8711). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [11167996](https://api.semanticscholar.org/CorpusID:11167996). 75. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-apj_76-0)** Peissker, Florian; Eckart, Andreas; Parsa, Marzieh (January 2020). ["S62 on a 9.9 year orbit around SgrA\*"](https://doi.org/10.3847%2F1538-4357%2Fab5afd). *[The Astrophysical Journal](https://en.wikipedia.org/wiki/The_Astrophysical_Journal "The Astrophysical Journal")*. **889** (1): 61. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[2002\.02341](https://arxiv.org/abs/2002.02341). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2020ApJ...889...61P](https://ui.adsabs.harvard.edu/abs/2020ApJ...889...61P). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.3847/1538-4357/ab5afd](https://doi.org/10.3847%2F1538-4357%2Fab5afd). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [211043784](https://api.semanticscholar.org/CorpusID:211043784). 76. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-p994_77-0)** GRAVITY Collaboration (2021). ["Detection of faint stars near Sagittarius A\* with GRAVITY"](https://www.aanda.org/articles/aa/pdf/2021/01/aa39544-20.pdf) (PDF). *Astronomy & Astrophysics*. **645**: A127. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[2011\.03058](https://arxiv.org/abs/2011.03058). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2021A\&A...645A.127G](https://ui.adsabs.harvard.edu/abs/2021A&A...645A.127G). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1051/0004-6361/202039544](https://doi.org/10.1051%2F0004-6361%2F202039544). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0004-6361](https://search.worldcat.org/issn/0004-6361). Retrieved December 29, 2024. 77. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-78)** Peißker, Florian; Eckart, Andreas; Zajaček, Michal; Basel, Ali; Parsa, Marzieh (August 2020). ["S62 and S4711: Indications of a Population of Faint Fast-moving Stars inside the S2 Orbit—S4711 on a 7.6 yr Orbit around Sgr A\*"](https://doi.org/10.3847%2F1538-4357%2Fab9c1c). *[The Astrophysical Journal](https://en.wikipedia.org/wiki/The_Astrophysical_Journal "The Astrophysical Journal")*. **889** (50): 5. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[2008\.04764](https://arxiv.org/abs/2008.04764). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2020ApJ...899...50P](https://ui.adsabs.harvard.edu/abs/2020ApJ...899...50P). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.3847/1538-4357/ab9c1c](https://doi.org/10.3847%2F1538-4357%2Fab9c1c). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [221095771](https://api.semanticscholar.org/CorpusID:221095771). 78. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-naess_79-0)** NĂŠss, S. (October 4, 2019). ["Galactic center S-star orbital parameters"](http://folk.uio.no/sigurdkn/s_stars). 79. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Matson_80-0)** Matson, John (October 22, 2012). ["Gas Guzzler: Cloud Could Soon Meet Its Demise in Milky Way's Black Hole"](https://web.archive.org/web/20130619093354/https://www.llnl.gov/news/newsreleases/2012/Oct/NR-12-10-07.html). Scientific American. Archived from [the original](https://www.llnl.gov/news/newsreleases/2012/Oct/NR-12-10-07.html) on June 19, 2013. Retrieved October 30, 2012. 80. ^ [***a***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Gillessen_2012_51%E2%80%9354_81-0) [***b***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Gillessen_2012_51%E2%80%9354_81-1) Gillessen, S.; Genzel, R.; Fritz, T. K.; Quataert, E.; Alig, C.; Burkert, A.; Cuadra, J.; Eisenhauer, F.; Pfuhl, O.; Dodds-Eden, K.; Gammie, C. F.; Ott, T. (January 2012). "A gas cloud on its way towards the supermassive black hole at the Galactic Centre". *Nature*. **481** (7379): 51–54\. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[1112\.3264](https://arxiv.org/abs/1112.3264). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2012Natur.481...51G](https://ui.adsabs.harvard.edu/abs/2012Natur.481...51G). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1038/nature10652](https://doi.org/10.1038%2Fnature10652). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0028-0836](https://search.worldcat.org/issn/0028-0836). [PMID](https://en.wikipedia.org/wiki/PMID_\(identifier\) "PMID (identifier)") [22170607](https://pubmed.ncbi.nlm.nih.gov/22170607). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [4410915](https://api.semanticscholar.org/CorpusID:4410915). 81. ^ [***a***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Witzel2014_82-0) [***b***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Witzel2014_82-1) [***c***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Witzel2014_82-2) Witzel, G.; Ghez, A. M.; Morris, M. R.; Sitarski, B. N.; Boehle, A.; Naoz, S.; Campbell, R.; Becklin, E. E.; G. Canalizo; Chappell, S.; Do, T.; Lu, J. R.; Matthews, K.; Meyer, L.; Stockton, A.; Wizinowich, P.; Yelda, S. (January 1, 2014). "Detection of Galactic Center Source G2 at 3.8 ÎŒm during Periapse Passage". *Astrophysical Journal Letters*. **796** (1): L8. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[1410\.1884](https://arxiv.org/abs/1410.1884). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2014ApJ...796L...8W](https://ui.adsabs.harvard.edu/abs/2014ApJ...796L...8W). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1088/2041-8205/796/1/L8](https://doi.org/10.1088%2F2041-8205%2F796%2F1%2FL8). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [36797915](https://api.semanticscholar.org/CorpusID:36797915). 82. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Bartos_83-0)** Bartos, Imre; Haiman, ZoltĂĄn; Kocsis, Bence; MĂĄrka, Szabolcs (May 2013). "Gas Cloud G2 Can Illuminate the Black Hole Population Near the Galactic Center". *Physical Review Letters*. **110** (22): 221102 (5 pages). [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[1302\.3220](https://arxiv.org/abs/1302.3220). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2013PhRvL.110v1102B](https://ui.adsabs.harvard.edu/abs/2013PhRvL.110v1102B). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1103/PhysRevLett.110.221102](https://doi.org/10.1103%2FPhysRevLett.110.221102). [PMID](https://en.wikipedia.org/wiki/PMID_\(identifier\) "PMID (identifier)") [23767710](https://pubmed.ncbi.nlm.nih.gov/23767710). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [12284209](https://api.semanticscholar.org/CorpusID:12284209). 83. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-Geometry_84-0)** de la Fuente Marcos, R.; de la Fuente Marcos, C. (August 2013). ["Colliding with G2 near the Galactic Centre: a geometrical approach"](https://doi.org/10.1093%2Fmnrasl%2Fslt085). *[Monthly Notices of the Royal Astronomical Society: Letters](https://en.wikipedia.org/wiki/Monthly_Notices_of_the_Royal_Astronomical_Society:_Letters "Monthly Notices of the Royal Astronomical Society: Letters")*. **435** (1): L19–L23. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[1306\.4921](https://arxiv.org/abs/1306.4921). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2013MNRAS.435L..19D](https://ui.adsabs.harvard.edu/abs/2013MNRAS.435L..19D). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1093/mnrasl/slt085](https://doi.org/10.1093%2Fmnrasl%2Fslt085). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [119287777](https://api.semanticscholar.org/CorpusID:119287777). 84. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-85)** Morris, Mark (January 4, 2012). ["Astrophysics: The Final Plunge"](https://doi.org/10.1038%2Fnature10767). *Nature*. **481** (7379): 32–33\. [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2012Natur.481...32M](https://ui.adsabs.harvard.edu/abs/2012Natur.481...32M). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1038/nature10767](https://doi.org/10.1038%2Fnature10767). [PMID](https://en.wikipedia.org/wiki/PMID_\(identifier\) "PMID (identifier)") [22170611](https://pubmed.ncbi.nlm.nih.gov/22170611). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [664513](https://api.semanticscholar.org/CorpusID:664513). 85. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-86)** Gillessen. ["Wiki Page of Proposed Observations of G2 Passage"](https://wiki.mpe.mpg.de/gascloud/ProposalList). [Archived](https://web.archive.org/web/20140201203116/https://wiki.mpe.mpg.de/gascloud/ProposalList) from the original on February 1, 2014. Retrieved October 30, 2012. 86. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-87)** ["A Black Hole's Dinner is Fast Approaching"](http://www.eso.org/public/news/eso1151/). ESO. December 14, 2011. [Archived](https://web.archive.org/web/20120213173904/http://www.eso.org/public/news/eso1151/) from the original on February 13, 2012. Retrieved February 27, 2015. 87. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-88)** H Hirschfeld, Robert (October 22, 2012). ["Milky Way's black hole getting ready for snack"](https://web.archive.org/web/20130619093354/https://www.llnl.gov/news/newsreleases/2012/Oct/NR-12-10-07.html). [Lawrence Livermore National Laboratory](https://en.wikipedia.org/wiki/Lawrence_Livermore_National_Laboratory "Lawrence Livermore National Laboratory"). Archived from [the original](https://www.llnl.gov/news/newsreleases/2012/Oct/NR-12-10-07.html) on June 19, 2013. Retrieved February 27, 2015. 88. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-89)** Taylor Tillman, Nola (April 28, 2014). ["Doomed Space Cloud Nears Milky Way's Black Hole as Scientists Watch"](https://www.space.com/25665-doomed-space-cloud-giant-black-hole.html). *[Space.com](https://en.wikipedia.org/wiki/Space.com "Space.com")*. Retrieved September 15, 2024. "Cosmic encounter that might reveal new secrets on how such supermassive black holes evolve; We get to watch it unfolding in a human lifetime, which is very unusual and very exciting" 89. ^ [***a***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-nature140721_90-0) [***b***](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-nature140721_90-1) Cowen, Ron (2014). ["Why galactic black hole fireworks were a flop : Nature News & Comment"](http://www.nature.com/news/why-galactic-black-hole-fireworks-were-a-flop-1.15591). *Nature*. [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1038/nature.2014.15591](https://doi.org/10.1038%2Fnature.2014.15591). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [124346286](https://api.semanticscholar.org/CorpusID:124346286). [Archived](https://web.archive.org/web/20150219013446/http://www.nature.com/news/why-galactic-black-hole-fireworks-were-a-flop-1.15591) from the original on February 19, 2015. Retrieved February 27, 2015. 90. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-91)** Pfuhl, Oliver; Gillessen, Stefan; Eisenhauer, Frank; Genzel, Reinhard; Plewa, Philipp M.; Thomas Ott; Ballone, Alessandro; Schartmann, Marc; Burkert, Andreas (2015). "The Galactic Center Cloud G2 and its Gas Streamer". *The Astrophysical Journal*. **798** (2): 111. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[1407\.4354](https://arxiv.org/abs/1407.4354). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2015ApJ...798..111P](https://ui.adsabs.harvard.edu/abs/2015ApJ...798..111P). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1088/0004-637x/798/2/111](https://doi.org/10.1088%2F0004-637x%2F798%2F2%2F111). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0004-637X](https://search.worldcat.org/issn/0004-637X). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [118440030](https://api.semanticscholar.org/CorpusID:118440030). 91. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-92)** ["How G2 survived the black hole at our Milky Way's heart - EarthSky.org"](http://earthsky.org/space/how-g2-survived-the-black-hole-at-our-milky-ways-heart). November 4, 2014. [Archived](https://web.archive.org/web/20160205014740/http://earthsky.org/space/how-g2-survived-the-black-hole-at-our-milky-ways-heart) from the original on February 5, 2016. Retrieved February 14, 2016. 92. **[^](https://en.wikipedia.org/wiki/Sagittarius_A*#cite_ref-93)** ["Simulation of gas cloud after close approach to the black hole at the centre of the Milky Way"](http://www.eso.org/public/images/eso1151a/). ESO. [Archived](https://web.archive.org/web/20150307130323/http://www.eso.org/public/images/eso1151a/) from the original on March 7, 2015. Retrieved February 27, 2015. - Backer, D. C. & Sramek, R. A. (October 20, 1999). "Proper Motion of the Compact, Nonthermal Radio Source in the Galactic Center, Sagittarius A\*". *[The Astrophysical Journal](https://en.wikipedia.org/wiki/The_Astrophysical_Journal "The Astrophysical Journal")*. **524** (2): 805–815\. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[astro-ph/9906048](https://arxiv.org/abs/astro-ph/9906048). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[1999ApJ...524..805B](https://ui.adsabs.harvard.edu/abs/1999ApJ...524..805B). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1086/307857](https://doi.org/10.1086%2F307857). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0004-637X](https://search.worldcat.org/issn/0004-637X). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [18858138](https://api.semanticscholar.org/CorpusID:18858138). - Gillessen, Stefan; et al. (February 23, 2009). "Monitoring stellar orbits around the Massive Black Hole in the Galactic Center". *The Astrophysical Journal*. **692** (2): 1075–1109\. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[0810\.4674](https://arxiv.org/abs/0810.4674). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2009ApJ...692.1075G](https://ui.adsabs.harvard.edu/abs/2009ApJ...692.1075G). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1088/0004-637X/692/2/1075](https://doi.org/10.1088%2F0004-637X%2F692%2F2%2F1075). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [1431308](https://api.semanticscholar.org/CorpusID:1431308). - Melia, Fulvio (2007). *The galactic supermassive black hole*. Princeton: Princeton Univ. [ISBN](https://en.wikipedia.org/wiki/ISBN_\(identifier\) "ISBN (identifier)") [978-0-691-13129-0](https://en.wikipedia.org/wiki/Special:BookSources/978-0-691-13129-0 "Special:BookSources/978-0-691-13129-0") . - O'Neill, Ian (December 10, 2008). ["Beyond Any Reasonable Doubt: A Supermassive Black Hole Lives in Centre of Our Galaxy"](https://www.universetoday.com/22104/beyond-any-reasonable-doubt-a-supermassive-black-hole-lives-in-centre-of-our-galaxy/). [Universe Today](https://en.wikipedia.org/wiki/Universe_Today "Universe Today"). - Osterbrock, Donald E. & Ferland, Gary J. (2006). [*Astrophysics of gaseous nebulae and active galactic nuclei*](https://archive.org/details/astrophysicsofga0000oste) (2nd ed.). Mill Valley, California: University Science Books. [ISBN](https://en.wikipedia.org/wiki/ISBN_\(identifier\) "ISBN (identifier)") [978-1-891389-34-4](https://en.wikipedia.org/wiki/Special:BookSources/978-1-891389-34-4 "Special:BookSources/978-1-891389-34-4") . - Reid, M. J.; Brunthaler, A. (December 2004). "The Proper Motion of Sagittarius A\*. II. The Mass of Sagittarius A\*". *[The Astrophysical Journal](https://en.wikipedia.org/wiki/The_Astrophysical_Journal "The Astrophysical Journal")*. **616** (2): 872–884\. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[astro-ph/0408107](https://arxiv.org/abs/astro-ph/0408107). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2004ApJ...616..872R](https://ui.adsabs.harvard.edu/abs/2004ApJ...616..872R). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1086/424960](https://doi.org/10.1086%2F424960). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0004-637X](https://search.worldcat.org/issn/0004-637X). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [16568545](https://api.semanticscholar.org/CorpusID:16568545). - Schödel, R.; et al. (October 2002). "A star in a 15.2-year orbit around the supermassive black hole at the centre of the Milky Way". *[Nature](https://en.wikipedia.org/wiki/Nature_\(journal\) "Nature (journal)")*. **419** (6908): 694–696\. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[astro-ph/0210426](https://arxiv.org/abs/astro-ph/0210426). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2002Natur.419..694S](https://ui.adsabs.harvard.edu/abs/2002Natur.419..694S). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1038/nature01121](https://doi.org/10.1038%2Fnature01121). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0028-0836](https://search.worldcat.org/issn/0028-0836). [PMID](https://en.wikipedia.org/wiki/PMID_\(identifier\) "PMID (identifier)") [12384690](https://pubmed.ncbi.nlm.nih.gov/12384690). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [4302128](https://api.semanticscholar.org/CorpusID:4302128). - Schödel, R.; [Merritt, D.](https://en.wikipedia.org/wiki/David_Merritt "David Merritt"); Eckart, A. (July 2009). "The nuclear star cluster of the Milky Way: proper motions and mass". *[Astronomy & Astrophysics](https://en.wikipedia.org/wiki/Astronomy_%26_Astrophysics "Astronomy & Astrophysics")*. **502** (1): 91–111\. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[0902\.3892](https://arxiv.org/abs/0902.3892). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2009A\&A...502...91S](https://ui.adsabs.harvard.edu/abs/2009A&A...502...91S). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1051/0004-6361/200810922](https://doi.org/10.1051%2F0004-6361%2F200810922). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0004-6361](https://search.worldcat.org/issn/0004-6361). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [219559](https://api.semanticscholar.org/CorpusID:219559). - Melia, Fulvio (2003). [*The black hole at the center of our galaxy*](https://archive.org/details/blackholeatcente0000meli). Princeton: Princeton University Press. [ISBN](https://en.wikipedia.org/wiki/ISBN_\(identifier\) "ISBN (identifier)") [978-0-691-09505-9](https://en.wikipedia.org/wiki/Special:BookSources/978-0-691-09505-9 "Special:BookSources/978-0-691-09505-9") . - Doeleman, Sheperd S.; et al. (September 2008). "Event-horizon-scale structure in the supermassive black hole candidate at the Galactic Centre". *Nature*. **455** (7209): 78–80\. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[0809\.2442](https://arxiv.org/abs/0809.2442). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2008Natur.455...78D](https://ui.adsabs.harvard.edu/abs/2008Natur.455...78D). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1038/nature07245](https://doi.org/10.1038%2Fnature07245). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0028-0836](https://search.worldcat.org/issn/0028-0836). [PMID](https://en.wikipedia.org/wiki/PMID_\(identifier\) "PMID (identifier)") [18769434](https://pubmed.ncbi.nlm.nih.gov/18769434). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [4424735](https://api.semanticscholar.org/CorpusID:4424735). - Eckart, Andreas; Schödel, Rainer; Straubmeier, Christian Michael; Straubmeier, Christian (2005). *The black hole at the center of the Milky Way*. London: Imperial College Press. [ISBN](https://en.wikipedia.org/wiki/ISBN_\(identifier\) "ISBN (identifier)") [978-1-86094-567-0](https://en.wikipedia.org/wiki/Special:BookSources/978-1-86094-567-0 "Special:BookSources/978-1-86094-567-0") . - Eisenhauer, F.; Schdel, R.; Genzel, R.; Ott, T.; Tecza, M.; Abuter, R.; Eckart, A.; Alexander, T.; et al. (November 10, 2003). "A Geometric Determination of the Distance to the Galactic Center". *[The Astrophysical Journal](https://en.wikipedia.org/wiki/The_Astrophysical_Journal "The Astrophysical Journal")*. **597** (2): L121–L124. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[astro-ph/0306220](https://arxiv.org/abs/astro-ph/0306220). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2003ApJ...597L.121E](https://ui.adsabs.harvard.edu/abs/2003ApJ...597L.121E). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1086/380188](https://doi.org/10.1086%2F380188). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0004-637X](https://search.worldcat.org/issn/0004-637X). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [16425333](https://api.semanticscholar.org/CorpusID:16425333). - [The Event Horizon Telescope Collaboration](https://en.wikipedia.org/wiki/Event_Horizon_Telescope "Event Horizon Telescope") (April 10, 2019). ["First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole"](https://doi.org/10.3847%2F2041-8213%2Fab0ec7). *[The Astrophysical Journal Letters](https://en.wikipedia.org/wiki/The_Astrophysical_Journal_Letters "The Astrophysical Journal Letters")*. **875** (1): L1. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[1906\.11238](https://arxiv.org/abs/1906.11238). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2019ApJ...875L...1E](https://ui.adsabs.harvard.edu/abs/2019ApJ...875L...1E). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.3847/2041-8213/ab0ec7](https://doi.org/10.3847%2F2041-8213%2Fab0ec7). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [145906806](https://api.semanticscholar.org/CorpusID:145906806). - Ghez, A. M.; et al. (April 1, 2003). "The First Measurement of Spectral Lines in a Short-Period Star Bound to the Galaxy's Central Black Hole: A Paradox of Youth". *[The Astrophysical Journal](https://en.wikipedia.org/wiki/The_Astrophysical_Journal "The Astrophysical Journal")*. **586** (2): L127–L131. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[astro-ph/0302299](https://arxiv.org/abs/astro-ph/0302299). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2003ApJ...586L.127G](https://ui.adsabs.harvard.edu/abs/2003ApJ...586L.127G). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1086/374804](https://doi.org/10.1086%2F374804). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [11388341](https://api.semanticscholar.org/CorpusID:11388341). - Ghez, A. M.; et al. (December 20, 2008). "Measuring Distance and Properties of the Milky Way's Central Supermassive Black Hole with Stellar Orbits". *[The Astrophysical Journal](https://en.wikipedia.org/wiki/The_Astrophysical_Journal "The Astrophysical Journal")*. **689** (2): 1044–1062\. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[0808\.2870](https://arxiv.org/abs/0808.2870). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2008ApJ...689.1044G](https://ui.adsabs.harvard.edu/abs/2008ApJ...689.1044G). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1086/592738](https://doi.org/10.1086%2F592738). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0004-637X](https://search.worldcat.org/issn/0004-637X). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [18335611](https://api.semanticscholar.org/CorpusID:18335611). - Reynolds, Christopher S. (September 2008). "Bringing black holes into focus". *[Nature](https://en.wikipedia.org/wiki/Nature_\(journal\) "Nature (journal)")*. **455** (7209): 39–40\. [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2008Natur.455...39R](https://ui.adsabs.harvard.edu/abs/2008Natur.455...39R). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1038/455039a](https://doi.org/10.1038%2F455039a). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0028-0836](https://search.worldcat.org/issn/0028-0836). [PMID](https://en.wikipedia.org/wiki/PMID_\(identifier\) "PMID (identifier)") [18769426](https://pubmed.ncbi.nlm.nih.gov/18769426). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [205040663](https://api.semanticscholar.org/CorpusID:205040663). - Wheeler, J. Craig (2007). *Cosmic catastrophes: exploding stars, black holes, and mapping the universe* (2nd ed.). Cambridge; New York: [Cambridge University Press](https://en.wikipedia.org/wiki/Cambridge_University_Press "Cambridge University Press"). [ISBN](https://en.wikipedia.org/wiki/ISBN_\(identifier\) "ISBN (identifier)") [978-0-521-85714-7](https://en.wikipedia.org/wiki/Special:BookSources/978-0-521-85714-7 "Special:BookSources/978-0-521-85714-7") . [OCLC](https://en.wikipedia.org/wiki/OCLC_\(identifier\) "OCLC (identifier)") [73954922](https://search.worldcat.org/oclc/73954922). - Peißker, F.; Zajaček, M.; Melamed, M.; Ali, B.; Singhal, M.; Dassel, T.; Eckart, A.; Karas, V. (June 2024). "Candidate young stellar objects in the S-cluster: Kinematic analysis of a subpopulation of the low-mass G objects close to Sgr A\*". *[Astronomy & Astrophysics](https://en.wikipedia.org/wiki/Astronomy_%26_Astrophysics "Astronomy & Astrophysics")*. **686**: A235. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[2406\.09916](https://arxiv.org/abs/2406.09916). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2024A\&A...686A.235P](https://ui.adsabs.harvard.edu/abs/2024A&A...686A.235P). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1051/0004-6361/202449729](https://doi.org/10.1051%2F0004-6361%2F202449729). [ISSN](https://en.wikipedia.org/wiki/ISSN_\(identifier\) "ISSN (identifier)") [0004-6361](https://search.worldcat.org/issn/0004-6361). - Rayne, Elizabeth (July 4, 2024). ["Swarm of dusty young stars found around our galaxy's central black hole"](https://arstechnica.com/science/2024/07/swarm-of-dusty-young-stars-found-around-our-galaxys-central-black-hole/). *Ars Technica*. Retrieved July 5, 2024. - [Is there a Supermassive Black Hole at the Center of the Milky Way?](https://arxiv.org/abs/0808.2624) ([arXiv](https://en.wikipedia.org/wiki/ArXiv "ArXiv") preprint) - [2004 paper deducing mass of central black hole from orbits of 7 stars](https://arxiv.org/abs/astro-ph/0306130) ([arXiv](https://en.wikipedia.org/wiki/ArXiv "ArXiv") preprint) - [ESO video clip of orbiting star](http://www.eso.org/public/archives/videos/old_video/eso0226a.mpg) (533 KB MPEG Video) - [The Proper Motion of Sgr A\* and the Mass of Sgr A\*](https://arxiv.org/abs/astro-ph/0408107) (PDF) - [NRAO article](http://www.nrao.edu/pr/1998/bhole/) regarding VLBI radio imaging of Sgr A\* - [Peering into a Black Hole](https://www.nytimes.com/video/science/100000003725182/peering-into-a-black-hole.html), 2015 *New York Times* video - [Image of supermassive black hole Sagittarius A\* (2022)](https://pweb.cfa.harvard.edu/news/9741/imagelist), Harvard Center for Astrophysics - [Video (65:30) – EHT conference presenting first image of Sgr A\*](https://www.youtube.com/watch?v=4Ws0iPDSqI4) on [YouTube](https://en.wikipedia.org/wiki/YouTube_video_\(identifier\) "YouTube video (identifier)") ([NSF](https://en.wikipedia.org/wiki/National_Science_Foundation "National Science Foundation"); 12 May 2022)
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