Gaia discovers a unique black hole

ESA’s Gaia mission has helped discover a new kind of black hole. The new family already has two members, and both are closer to Earth than any other black hole that we know of.

The two black holes were discovered by studying ultra-precise measurements of stellar positions and motions in Gaia’s third data release.

A strange ‘wobble’ in the movement of two stars on the sky indicated that they are orbiting a very massive object. In both cases, the objects are approximately ten times more massive than our Sun. Other explanations for these massive companions, like double-star systems, were ruled out since they do not seem to emit any light.

Gaia’s second black hole, BH2, is located 3800 light-years away from Earth. It is a binary system consisting of a red giant star and likely a black hole.

In this animation of Gaia BH2, created in Gaia Sky, the orbits are accurately sized, but the back hole diameter is not to scale.

Access the broadcast quality version of the video.