The black hole is thought to have a mass of 70 times greater than the sun – three times more than usual.
A black hole so big that scientists say it should not exist has been discovered 15,000 light years away from Planet Earth.
Black holes are formed after stars die, collapse and explode, and are understood to have a mass about 20 times that of the sun.
However, the latest discovery, named LB-1, has a mass 70 times greater than that of the sun, making researchers question current theories around the size of the interstellar phenomenon.
Professor Liu Jifeng, the head of an international research team that made the discovery, said: “Black holes of such mass should not even exist in our galaxy, according to most of the current models of stellar evolution.
“We thought that very massive stars with the chemical composition typical of our galaxy must shed most of their gas in powerful stellar winds, as they approach the end of their life.
“Therefore, they should not leave behind such a massive remnant.
“LB-1 is twice as massive as what we thought possible.”