Cosmic Scale
Gaia BH3
Dormant black hole · 1,926 light-years
How big is Gaia BH3?
Gaia BH3 is about 195 km across.
See Gaia BH3 in 3D, at true scale
Gaia BH3 is a black hole of 33 Suns found in 2024 from the wobble of a star orbiting it every 11.6 years. It is the most massive stellar black hole known in our galaxy, and one of the nearest.
At a glance
| Diameter | 195 km |
|---|---|
| Mass | 6.56 × 10³¹ kg |
| Diameter compared with Earth | 0.015 × Earth |
| Distance | 1,926 light-years |
| Found | 2024, from Gaia data |
| Companion | An old, metal-poor giant star |
Good to know
- Its mass is like the black holes whose collisions are picked up as gravitational waves.
- Its companion is almost pure hydrogen and helium, a sign it came from an early generation of stars.
- It gives off no light; it was found only by its pull on the other star.
- Next smaller: Cygnus X-1 · 125 km
- Next larger: Mimas · 396 km