A near-Earth black hole has been discovered

It’s a black hole 10 times heavier than the Sun and 100 million times smaller — so dense that even light can’t escape. Details by Herve Poirier, editor-in-chief of Science magazine Epsilon.

franceinfo: And this cosmic monster is 1500 light years away?

Herve Poirier: That means that light, if emitted by something, takes 1500 years to reach us. Well, it’s not even close to it (it only takes 8 minutes for light to travel from the Sun), but at the scale of the Milky Way, it’s the inner suburbs – a little more than 1% of the size of our galaxy.

Physicists have been imagining these black holes for hundreds of years. And This recent discovery will date. And not just because it’s the closest to Earth ever discovered — three times closer than the previous record. Especially since it was the first truly dark black hole.

What exactly is darkness?

The other 20 black holes known so far in the Milky Way are all engulfing clouds of gas or a nearby star: so thanks to the X-rays emitted during this violent feast, they’re relatively easy to detect. But no: this black hole curls up in its darkness and sleeps. There, in his place, the telescopes actually saw nothing. No light.

How do we know he’s there if we can’t see anything?

This is the big question we have been asking ourselves for 100 years. Its existence is actually demonstrated by its companion orbiting it: a star comparable to our Sun. The strange motion of this star, recorded Gaia Space Telescope, fascinated astrophysicists. Their calculations are finally legitimate: the only way to explain this trajectory is around a ten-times-massier and infinitely dark companion—the researchers wonder, even if there aren’t actually two black holes orbiting each other. .

Will this discovery invite others?

This close proximity suggests that passive black holes are more likely than turbulent black holes. The team estimates they could quickly find a dozen more in the Kia data they’re analyzing. Knowing that models predict there are 100 million more black holes in the galaxy.

So far only the most agitated ones have been seen in the sky. We begin to see others around us, lurking in the darkness. We begin to see the dark side of the galaxy.