# List of black holes

This list of black holes (and stars considered probable candidates) is organized by mass (including black holes of undetermined mass); some items in this list are galaxies or star clusters that are believed to be organized around a black hole. Messier and New General Catalogue designations are given where possible.

## Supermassive black holes and candidates

* 1ES 2344+514
* Ton 618 (this quasar has possibly the biggest black hole ever found, estimated at 66 billion solar masses)
* 3C 371
* 4C +37.11 (this radio galaxy is believed to have binary supermassive black holes)
* AP Lib
* S5 0014+81 (said to be a compact hyperluminous quasar, estimated at 40 billion solar masses)
* APM 08279+5255 (contains one of the largest black holes, estimated at 10-23 billion solar masses; previous candidate for largest)
* Arp 220
* Centaurus A
* Fornax A
* HE0450-2958
* IC 1459
* Messier 31 (or the Andromeda Galaxy)
* Messier 32
* Messier 51 (or the Whirlpool Galaxy)
* Messier 60
* Messier 77
* Messier 81 (or Bode's Galaxy)
* Messier 84
* Messier 87 (or Virgo A)
* Messier 104 (or the Sombrero Galaxy)
* Messier 105
* Messier 106
* Quiescent (Galaxy) (Black Hole at the center of the Andromeda Galaxy)
* Mrk 421
* Mrk 501
* NGC 821
* NGC 1023
* NGC 1097
* NGC 1271
* NGC 1277
* NGC 1332
* NGC 1566
* NGC 2787
* NGC 3079
* NGC 3115
* NGC 3377
* NGC 3384
* NGC 3998
* NGC 4151
* NGC 4261
* NGC 4438
* NGC 4459
* NGC 4473
* NGC 4486B (a satellite galaxy of Messier 87)
* NGC 4564
* NGC 4579
* NGC 4596
* NGC 4697
* NGC 4889
* NGC 4945
* NGC 5033
* NGC 6251
* NGC 7052
* NGC 7314
* PKS 0521-365
* Q0906+6930 (a blazar organized around a supermassive black hole)
* RX J1131 (first black hole whose spin was directly measured)
* Sagittarius A*, which is in the center of the Milky Way

### Types

* Quasar
* Supermassive black hole
* Hypercompact stellar system (hypothetical object organized around a supermassive black hole)

## Intermediate-mass black holes and candidates

* Cigar Galaxy (Messier 82, NGC 3034)
* GCIRS 13E
* HLX-1
* M82 X-1
* Messier 15 (NGC 7078)
* Messier 110 (NGC 205)
* Sculptor Galaxy (NGC 253)
* Triangulum Galaxy (Messier 33, NGC 598)

## Stellar black holes and candidates

* 1E1740.7-2942 (Great Annihilator), 340 ly from Sgr A*
* 4U 1543-475/IL Lupi
* A0620-00/V616 Mon (once thought to be the closest to Earth known, at about 3,000 light years)
* CXOU J132527.6-430023 (a candidate stellar mass black hole outside of the Local Group)
* Cygnus X-1
* Cygnus X-3
* GRO J0422+32 (possibly the smallest black hole yet discovered)
* GRO J1655-40/V1033 Sco (at one time considered the smallest black hole known)
* GRS 1124-683/GU Mus
* GRS 1915+105/V1487 Aql
* GS 2000+25/QZ Vul
* GX 339-4/V821 Ara
* IGR J17091-3624 (candidate smallest known stellar black hole)
* LB-1 (name of both a galactic B-type star and a very closely associated over-massive stellar-mass black hole)
* M33 X-7 (stellar black hole with the most massive stellar companion, located in the Triangulum Galaxy)
* MOA-2011-BLG-191/OGLE-2011-BLG-0462 (first known isolated stellar black hole)
* SN 1997D (in NGC 1536)
* SS 433
* V404 Cyg
* V Puppis
* XTE J1118+480/KV UMa
* XTE J1550-564/V381 Nor
* XTE J1650-500 (at one time considered the smallest black hole known)
* XTE J1819-254/V4641 Sgr
* LMC X-1 (first X-ray source in the Large Magellanic Cloud)

### Black holes detected by gravitational wave signals

As of February 2019, 10 mergers of binary black holes have been observed. In each case two black holes merged to a larger black hole. In addition, one neutron star merger has been observed (GW170817), forming a black hole. In addition, over 30 alerts have been issued since April 2019, of black hole merger candidates.
* GW 150914

## Multiple black hole systems
### Binary black holes

* EGSD2 J142033.66 525917.5 core black holes — galaxy hosting a dual AGN
* OJ 287 core black holes — a BL Lac object with a candidate binary supermassive black hole core system
* PG 1302-102 – the first binary-cored quasar — a pair of supermassive black holes at the core of this quasar
* SDSS J120136.02+300305.5 core black holes — a pair of supermassive black holes at the centre of this galaxy
In addition, the signal of several binary black holes merging into a single black hole and in so doing producing gravitational waves have been observed by the LIGO instrument. These are listed above in the section Black holes detected by gravitational wave signals.

### Trinary black holes

As of 2014, there are 5 triple black hole systems known.
* SDSS J150243.09+111557.3 (SDSS J1502+1115) core black holes — the three components are distant tertiary J1502P, and the close binary pair J1502S composed of J1502SE and J1502SW
* GOODS J123652.77+621354.7 core black holes of triple-clump galaxy
* 2MASX J10270057+1749001 (SDSS J1027+1749) core black holes