Gaia BH1
What is Gaia BH1?
Black holes & quasars· Distance 1,560 ly. A dormant black hole found by the Gaia satellite from nothing but the tiny wobble of a Sun-like star circling it every 186 days. It swallows no gas and emits no X-rays. At discovery it was the closest black hole known to Earth. Its size, as an event horizon, is only about 28 km across in radius — the span of a city.
📍 Visible from where you are right now — computed in your browser
bearing · altitude · rise time · best time tonight
Where Gaia BH1 is in your sky right now: https://nowsky.org/solar/sky?sel=gaia bh1 — location and time set automatically, no login.
Its place in the sky
A black hole, in the direction of Ophiuchus.
Mass, distance, nature
| Mass | ~9.6 Suns |
|---|---|
| Distance | ~1,560 ly |
| Companion | Sun-like G star, 186-day orbit |
| Size | event-horizon radius ~28 km (from the mass) |
| Discovered | 2022, Gaia astrometry |
Figures are representative approximations. Source: compiled from NASA and IAU public data.
Discovery and name
Found in 2022 by Gaia from the wobble of a Sun-like star — the nearest black hole at 1,560 ly.
Frequently asked
- What is the mass of Gaia BH1?
- ~9.6 Suns.
- How far is Gaia BH1 from Earth?
- ~1,560 ly.
- When was Gaia BH1 discovered?
- 2022, Gaia astrometry.
- Where in the sky is Gaia BH1?
- In the direction of Ophiuchus.
- Where is Gaia BH1 in the sky right now?
- Open the sky view for your location and time and it shows the position in the sky right now.
Quiet black holes are the common kind — Gaia's census begins
The Milky Way is thought to hold around a hundred million stellar black holes, yet only a few dozen have been confirmed, nearly all of them feeding on a companion's gas and shining in X-rays. The great majority are "quiet" black holes that eat nothing and were simply invisible. Gaia BH1 is the first specimen caught from that majority, and being found by position measurement alone, it showed black holes can be counted without X-rays.
Gaia found BH1 and BH2 in its 2022 data and BH3 in 2024, and the full orbital data due from 2026 onward are expected to yield dozens more. Their numbers and the distribution of their orbits will answer statistically how massive stars die and how hard black holes are kicked at birth. Measuring the faint wobble of nearby stars has become the way to count the darkest objects in the universe.
The black hole in depth
Gaia BH1 is a black-hole binary about 1,560 light-years away in Ophiuchus. The black hole weighs roughly 9.6 Suns, and its partner is a G-type main-sequence star almost identical to the Sun, tracing a long elliptical orbit every 186 days. Announced in 2022 as the nearest black hole to Earth, it lies less than half the distance of the previous record holder, A0620-00.
The discovery method is what makes it special. Black holes are usually spotted by the X-rays from gas stripped off a companion, but here the two bodies are far apart and nothing glows. ESA's Gaia satellite, measuring stellar positions to microarcseconds over several years, caught the star tracing a tiny ellipse on the sky because of an unseen heavy partner. Millions of such dormant black holes may lurk in the galaxy.
The companion star is magnitude 13.8, a challenge for small telescopes, and the black hole itself is of course invisible. Select Gaia BH1 in the Sky view to see its place within Ophiuchus, and open the nearby-stars 3D view to get a feel for its distance among the Sun's stellar neighbours.
Related
Figures are representative approximations. Simulated positions use J2000 mean elements.