IC 10

IC 10

IC 10. Credit: Adam Block/NOAO/AURA/NSF.

IC 10 is a nearby dwarf irregular galaxy that is home to the most massive known stellar black hole – IC 10 X-1. IC 10 lies approximately 1.8 million light-years away in the constellation Cassiopeia. It is the only known starburst galaxy in the Local Group and is particularly rich in Wolf-Rayet stars, one of which is the companion of IC 10 X-1.


IC 10 was discovered by Lewis Swift in 1889 but not suspected of being extragalactic until the 1930s.


visual magnitude 10.4
angular size 6.8' × 5.9'
position RA 00h 20m 17.3s,
Dec +59° 18' 14"
other designations UGC 192, PGC 1305