A group of astronomers from the European Southern Observatory, or ESO, and other institutes has discovered a black hole that’s only 1000 light-years from Earth. While the distance is vast, the new black hole is closer to our Solar System than any other black hole found so far. The black hole forms part of a triple system that can be seen with the naked eye.
The astronomers found evidence for the black hole by tracking its two companion stars using the MPG/ESO 2.2-meter telescope at the La Silla Observatory in Chile. The scientists were “totally surprised” when they realize that this was the first stellar system with the black hole that can be seen with the unaided eye. The team says that the stars can be viewed from the southern hemisphere on a dark, clear night without binoculars or a telescope.
The system is called HR 6819 and was initially observed as a part of a study of double-star systems. They later discovered the third, previously undiscovered body in the HR 6819 system, a black hole. Observations made with the FEROS spectrograph show that one of the two visible stars orbits an unseen object every 40 days.
The team says that the second star orbits at a long distance from the inner pair. The team says that the hidden black hole in the system is one of the first stellar-mass black holes found that do not interact violently with their environment. The lack of interaction with its environment makes the black hole appear truly black. Its mass was calculated by studying the orbit of the star in the inner pair.
Astronomers have spotted a few dozen black holes in the galaxy so far, and nearly all strongly interact with their environment making their presence known by releasing X-rays. The team believes that the discovery of this new silent and invisible blackhole provides clues that could help scientists to find other hidden black holes in the Milky Way galaxy.