Black hole
Gaia BH1
The nearest known black hole — quiet, no disc (lensing only)
The nearest known black hole to Earth (1,560 light-years). Since it swallows no matter it has no disc and no X-rays; its existence is known only from the orbit of its companion star (Gaia DR3, El-Badry et al. 2023). Here too, only the gravitational lensing of background stars and the shadow of its 28 km event horizon can be seen.
| Mass | 9.62 solar masses |
|---|---|
| Event horizon radius | 28 km: the size of a city |
| Time for light to circle the event horizon once | 6.0 × 10⁻⁴ seconds |
| Mass | 9,62 M☉ |
| Distance | 480 pc (1,560 light-years) |
| Orbital period | 185.6 days |
| Separation | 1.4 AU |
| Status | Dormant — no accretion |
| Discovery | 2022 (Gaia DR3 astrometrisi) |
The event horizon is the boundary where the escape velocity equals the speed of light: nothing inside, not even light, can get out. Its radius grows in direct proportion to the mass (the Schwarzschild radius, for a non-rotating black hole).