Cosmic Scale
Gaia BH1
Dormant black hole · 1,560 light-years
How big is Gaia BH1?
Gaia BH1 is about 56.8 km across.
See Gaia BH1 in 3D, at true scale
Gaia BH1 is the closest known black hole to Earth, found not by any glow but by watching a Sun-like star swing around something invisible. It is dormant: no disk, no X-rays, nothing falling in.
At a glance
| Diameter | 56.8 km |
|---|---|
| Mass | 1.91 × 10³¹ kg |
| Diameter compared with Earth | 0.004 × Earth |
| Distance | 1,560 light-years |
| Orbit | 186 days |
| Found | 2022, from Gaia data |
Good to know
- Its companion orbits at roughly Earth's distance from the Sun — a normal star circling a black hole.
- How such a pair survived the supernova that made the black hole is still unexplained.
- Most known black holes are eating; quiet ones like this are likely far more common and far harder to find.
- Next smaller: Phobos · 22.2 km
- Next larger: Cygnus X-1 · 125 km