Astronomers have discovered the closest black hole to Earth. It's so close that its sister stars can be seen with the naked eye.
Wednesday's announcement backs up the theory that there are lots of these small black holes in our galaxy, but we just don't see them.
The European Southern Observatory provided an illustration of the discovery. It shows the orbits of the object in the HR 6819 triple system.
The group is made up of an inner binary with one star, orbit in blue, and a newly discovered black hole, orbit in red, as well as a third star in a wider orbit, blue.
The team originally believed there were only two objects, the two stars, in the system. However, as they analyzed their observations, they revealed a third, previously undiscovered body in HR 6819: a black hole, the closest ever found to Earth, about 1,000 light years away.
The black hole is invisible, but it makes its presence known by its gravitational pull, which forces the luminous inner star into an orbit. The objects in this inner pair have roughly the same mass and circular orbits.
Black holes usually can only be seen if astronomers spy star stuff falling into them but most of the time nothing is close enough to fall in.