kareem el-badry | scienceinfo.net

Two black holes closest to Earth discovered, of a kind never seen before
Two black holes lurking in Earth's backyard, just 1,560 and 3,800 light-years away, represent a type astronomers have never seen before.
Unexpectedly discovered a black hole near the Earth that so far we did not know
The newly discovered black hole lies in the star system HR 6819, 1,011 light-years from Earth and four times the mass of the Sun.