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stellar black hole · closest known stellar-mass black hole

Gaia BH1

This black hole was found without seeing it — a perfectly ordinary star nearby was swinging round something invisible! It is the closest one we know about, and it is quietly doing nothing at all.

🚀 Travel there
Gaia BH1 — Drawn, not photographed.

What it is

Quiet stellar-mass black hole (~10 solar masses) orbited by a Sun-like star; found purely from its gravity.

Stellar black hole: What is left when the most massive stars collapse. Every kind of thing there is →

Can you see it?

No. No telescope on Earth will show you this one; it is here to be understood, not seen. It is here because it is worth knowing about — and because leaving it out would make the sky look emptier than it is.

Worth knowing about Gaia BH1

In weight, about 10 times the Sun's mass. On the 100-meter-track scale model of the Milky Way, Gaia BH1 would be about 1.6 meters from the Sun — roughly as tall as an adult. Light takes 2 thousand years to get here from Gaia BH1, so what you are looking at is Gaia BH1 as it was 2 thousand years ago.

What makes it worth knowing
Closest known stellar-mass black hole to Earth; found quietly via gravity, not X-ray feeding, hinting more 'sleeping' black holes may be hiding in the galaxy.
How did anyone measure the Earth in the first place?
The numbers
Distance from us~1,560 light-years

Next to it

The Milky Wayspiral galaxyNaked eyeProxima CentauristarWith effortAlpha Centauri A & Bbinary star systemNaked eyeSiriusstarNaked eyeVegastarNaked eyeArcturusstarNaked eye
📖 How the Milky Way fits together

Then go outside

Not this one. But the sky over your head is full of ones you can see, and the Planetarium knows which.

🌙 Plan an evening outside🌌 Everything else in the sky