Astronomers have discovered a stellar black hole 15,000 light-years away that is 70 times the mass of the Sun. It has been named as the black hole LB-1 which was formed due to the gravitational collapse of a star and it is too big to exist in our galaxy.
Scientists have found a total of 15 supposed stellar black holes and they think there are countless others in our galaxy. Most of these black hole candidates are closer to Sagittarius A* which is the super massive black hole at the center of the Milky Way galaxy.
After observing these black holes, it has been estimated that a stellar black hole in our galaxy can be 20 times the mass of the Sun - 20 solar masses. However, the unpredicted stellar black hole, LB-1 is about 70 solar masses.
Prof. Liu Jifeng, the chief of the new study published in the journal Nature explained, “Black holes of such mass should not even exist in our galaxy, according to most of the current models of stellar evolution.”
English scientist John Michell suggested a technique in the year 1783 and that has been followed by the research team to make their observations of the stellar-mass black hole. The team was in search of stars under the influence of invisible objects instead of looking for X-ray signatures of a black hole holding cosmic bodies. The invisible objects are being supposed as a black hole.
Researchers used China's Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST)to survey the sky to look for these invisible objects. Following the discovery of a binary system of star and black hole, scientists used the 10.4 m Gran Telescopio Canarias and the 10 m Keck I telescope to find their physical parameters.
The scientists also discovered a star eight times the mass of the sun orbiting a 70 solar-mass black hole in 79 days. LIGO Director Prof. David Reitze said, “This discovery forces us to re-examine our models of how stellar-mass black holes form.”