The closest black hole yet discovered is a mere 1,000 lightyears away, reveals ESO study
The European Southern Observatory (ESO) has announced that it has discovered a black hole just 1,000 light-years away from Earth. Astronomers were studying the double star system HR 6819 when they found the black hole hiding in it.
Study authors used the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory in Chile for the study.
This artist’s impression shows the orbits of the objects in the HR 6819 triple system. This system 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 object, another star, in a wider orbit (also in blue). Image credit: ESO/L. Calçada
Researchers say that one of the two visible stars orbits an unseen object every 40 days. They further discovered that the second star is at a larger distance from the inner pair. Study authors found that the unseen object had a mass that was four times that of the Sun, reaching the conclusion that it had to be a black hole.
The black hole found in the star system HR 6819 is one of the very first stellar-mass black holes “which do not interact violently with their environment and, therefore, appear truly black.”
Till date, only a couple of dozen black holes have been spotted in our galaxy. Most of them strongly interact with their environment and they release powerful X-rays during the interaction, making their presence felt.
Scientists believe that many more black holes could be found in the future.
“We realised that another system, called LB-1, may also be such a triple, though we'd need more observations to say for sure,” revealed Marianne Heida, another co-author of the study.
In follow-up work to the study, Petr Hadrava aims to find out more about the light being given off by HR 6819 and in-process find out the identities of the two stars.