Astronomers have found a stellar-mass black hole , around 70 times the mass of the Sun , in the Milky Way, at 15 thousand light-years from Earth.
According to current models of stellar evolution, its size is impossible, at least not in our galaxy. It was named LB-1. "Black holes of such mass should not even exist in our galaxy, according to most of the current models of stellar evolution," said astronomer Jifeng Liu of the National Astronomical Observatory of China. Liu and his colleagues were using the Large Sky Area Multi-Object Fiber Spectroscopic Telescope in China to search for black holes using an indirect method, based on observance of other cosmic objects graviting near the invisible black holes. A star eight times heavier than our own Sun was orbiting the vast black hole every 79 days.
One scenario could be that LB-1 formed from the collision of two black holes. Other possibility could be a fallback supernova, in which material ejected from the dying star falls immediately back into it, resulting in the direct formation of a black hole. Once discovered, the LB-1 has suddenly become one of the most interesting objects in the Milky Way. The discovery could re-write our understanding of how such vast, mysterious objects form, scientists say. Our Milky Way galaxy is thought to contain 100 million such stellar black holes.