# Astronomy:List of nearest black holes

Short description: Wikimedia list article

This list contains black holes relatively near the Solar System (within our Milky Way galaxy). To make it easier to compare distances, our nearest star aside from the Sun—Proxima Centauri—is about 4.24 light years away and our Milky Way galaxy is approximately 185000 light years in diameter.

Most black holes are thought to be solitary and not in a binary (or more) system. However, it is nearly impossible to detect such a black hole aside from measuring its gravitational distortions on the light from visually nearby objects. Black holes in binary systems, despite constituting a minority of all black holes, are much easier to detect. As of October 20, 2020, it is now questioned whether the first item in the below list (HR 6819) is actually a black hole. Two published papers and one pre-print paper argue that HR 6819 is not in fact a trinary system, including a black hole, but rather a binary system with two mainstream stars.[1]

## List

Distance System Component Notes and additional references
(ly) (kpc) Designation Description Right ascension[2]
(Epoch J2000.0)
Declination[2]
(Epoch J2000.0)
Disco­very
date[3]
Desig­nation Stel­lar
class
Mass
(M☉)
1120±70 0.34±0.02 HR 6819
(QV Tel)
Triple star system with inner binary orbit t=40.333 ± 0.004 d [4]  18h 17m 07.532s[4] −56° 01′ 24.088″[4] 2020 Aa B3III[5] 6.3±0.1
Ab BH >5.0±0.4 Possibly a black hole, but not confirmed yet.[6] If confirmed, it is the first known black hole in a star system that is visible to the naked eye
B Be[5] Orbit and mass unknown
1500 0.460±0.007 V723 Monocerotis Binary star system with orbit t=59.9 d  06h 29m 04.659s −05° 34′ 20.23″ 2021 A BH 3.04±0.06 Lower mass gap black hole candidate nicknamed "The Unicorn"
B K0/K1III[7] 1.00±0.07
3000±300 ~0.858 A0620-00 (V616 Mon) Binary star system with orbit t=7.75 h  06h 22m 44.503s[8] −00° 20′ 44.72″[8] 1986 A BH 11.0±1.9 Black hole candidate
B K[5] 0.5±0.3
5400+6900
−1900
1.7±1.4 GRS 1124-683 (GU Muscae) Binary star system with orbit t=10.38 h  11h 26m 26.60s −68° 40′ 32.3″ 1991 Jan 20 A BH 6.95±1.1 Black hole candidate
B K 0.9±0.3
5720±300 1.7±0.1 XTE J1118+480  11h 18m 11s 48° 02′ 13″ 2000 A BH 6–6.5
B M 0.2
6000±375[9] 1.86 ± 0.12[9] Cygnus X-1 (Cyg X-1) Binary star system with orbit t=5.6 d  19h 58m 21.67595s[10] +35° 12′ 05.7783″[10] 1971 April–May Cyg X-1 BH 15±1 The first X-ray source widely accepted to be a black hole.
HDE 226868 O[11] 30±10
7400±1500 2.3±0.46 LB-1 B-type star with orbit t=78.9 d  06h 11m 49.0763s[12] +22° 49′ 32.686″[12] 2019 A BH 68+11
−13
Mass uncertain based on parallax and distance
B B 9.2+0.9
−1.2
7800±460 2.39±0.14 V404 Cygni Binary star system with orbit t=6.5 d  20h 24m 03.83s[13] +33° 52′ 02.2″[13] 1989 May 22 A BH 9 The first black hole to have an accurate parallax measurement for its distance from our solar system
B K[2] 0.7 Early K giant star
8100±1000 2.49±0.30 GRO J0422+32 Binary star system with orbit t=5.09 h  04h 21m 42.723s +32° 54′ 26.94″ 1992 Aug 5 A BH 3.97±0.95 May be a massive neutron star
B M1 0.5±0.1
8800±2300 2.7±0.7 GS 2000+25  20h 02m 50s +25° 14′ 11″ 1988 A BH 7.5
B M 0.5
11100±700 3.4±0.2 Cygnus X-3 Binary star system with orbit t=4.8 h  20h 32m 25.766s +40° 57′ 28.26″ 1967 Cyg X-3 BH 2.4+2.1
−1.1

[14]
V1521 Cyg WN 10.3+3.9
−2.8

[14]
11900±3600 3.7±1.1 GRO J1655-40 Binary star system with orbit t = 2.6 d  16h 54m 00.137s −39° 50′ 44.90″ 1994 A BH 5.31±0.07
V1033 Sco F5IV 1.9±0.3
25600±600 7.86±0.2 Sagittarius A* Supermassive black hole  17h 45m 40.0409s −29° 0′ 28.118″ 1974 BH 4300000 Center of galaxy
29700±2700 9.1±0.8 4U 1543-475 Binary star system with orbit t = 26.8 h  15h 47m 08.277s −47° 40′ 10.28″ 1971 A BH 9.4±2.0
B A2V 2.7±1.0

## References

1. Research Consortium on Nearby Stars, GSU (2007-09-17). "The One Hundred Nearest Star Systems". Research Consortium On Nearby Stars. Retrieved 2007-11-06.
2. Before 1900: earliest certain recorded observation. 1900–1930: first catalogued. After 1930: earliest trigonometric or spectroscopic parallax.
3. Rivinius, Th.; Baade, D.; Hadrava, P.; Heida, M.; Klement, R. (May 2020). "A naked-eye triple system with a nonaccreting black hole in the inner binary". Astronomy & Astrophysics 637 (L3): 11. doi:10.1051/0004-6361/202038020. Bibcode2020A&A...637L...3R.
4. Yungelson, L. (May 2008), "Evolution of low-mass binaries with black-hole components", New Astronomy Reviews 51 (10–12): 860–868, doi:10.1016/j.newar.2008.03.017, Bibcode2008NewAR..51..860Y
5. Jayasinghe, T. (2021). "A unicorn in monoceros: The 3 M⊙ dark companion to the bright, nearby red giant V723 Mon is a non-interacting, mass-gap black hole candidate". Monthly Notices of the Royal Astronomical Society 504 (2): 2577–2602. doi:10.1093/mnras/stab907.
6. Liu, Q. (July 2007), "A Catalogue of low-mass X-ray binaries in the Galaxy, LMC, and SMC (Fourth edition)", Astronomy and Astrophysics 469 (2): 807–810, doi:10.1051/0004-6361:20077303, Bibcode2007A&A...469..807L
7. Reid, M. (December 2011), "The Trigonometric Parallax of Cygnus X-1", The Astrophysical Journal 742 (2): 83–88, doi:10.1088/0004-637X/742/2/83, Bibcode2011ApJ...742...83R
8. van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode2007A&A...474..653V
9. Sota, A. (April 2011), "The Galactic O-Star Spectroscopic Survey. I. Classification System and Bright Northern Stars in the Blue-violet at R ~ 2500", The Astrophysical Journal Supplement 193 (2): 24–74, doi:10.1088/0067-0049/193/2/24, Bibcode2011ApJS..193...24S
10. Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
11. Cutri, R. M.; Skrutskie, M. F.; Van Dyk, S.; Beichman, C. A.; Carpenter, J. M.; Chester, T.; Cambresy, L.; Evans, T. et al. (2003). "VizieR Online Data Catalog: 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)". VizieR On-line Data Catalog: II/246. Originally Published in: 2003yCat.2246....0C 2246. Bibcode2003yCat.2246....0C.
12. Zdziarski, A. A.; Mikolajewska, J.; Belczynski, K. (2013). "Cyg X-3: A low-mass black hole or a neutron star". Monthly Notices of the Royal Astronomical Society 429: L104–L108. doi:10.1093/mnrasl/sls035. Bibcode2013MNRAS.429L.104Z.