Astronomers have discovered the closest black hole to the solar system to date in galaxy HR 6819, just 1011 light-years away. At astronomical scale, a thousand light-years are very close. The discovery also means there may be a large number of small black holes in the Milky Way. The study was published in the journal Astronomy and Astrophysics. Astronomers have studied HR 6819 for a long time, not looking for a black hole, but on its binary system.
One of the stars rotates more than 200 times faster than the sun’s equator. Astronomers have observed that HR 6819 is not a standard binary system, and that the galaxy has a third object, an invisible object that is at least 4.2 times the mass of the sun. It can’t be an ordinary star, because a star of this size can be easily detected. Because it’s too heavy it can’t be a neutron star. There is only one possibility left: black holes.