Astronomers have discovered in the southern sky the closest black hole yet to Earth.
The black hole - described as the invisible gravitational ghoul - is only about 1,000 light-years away from Earth, and it orbits with two stars in a triple system.
The two accompanying stars can already be seen with the naked eye, but only from the southern hemisphere, according to discoverers under the supervision of Thomas Revinus of the European Southern Observatory "Eso" in the journal Astronomy and Astrophysics.
For comparison: our galaxy, the Milky Way, has a diameter of about 120,000 light years. A light-year is the distance light travels in one year.
"This system contains the closest black star to Earth we know so far," Revinus said in a statement to the European Southern Observatory.
Thanks to the relatively short distance, the accompanying stars can be seen on dark and clear nights of the Southern Hemisphere without any aids.
And unlike most models known to this size, the black hole in the triple system is actually black and invisible. This is because he does not eat any of his surroundings right now.