Recently, in a paper published in Nature Astronomy, scientists reported the discovery of an ancient supermassive black hole, one that existed very early in life of the Universe. While some enthusiasts have claimed that the observation of these gigantic black holes has disproved the theory of the Big Bang, this is a hasty conclusion. However, it is certainly true that the existence of very early supermassive black holes will require astronomers to rethink some things.
Most black holes are made when a very massive star burns through its fuel and then collapses under the weight of its own gravity. Stellar-mass black holes are typically in the range of 5 to 100 times the mass of the Sun.
In contrast, the supermassive black holes at the centers of galaxies are much bigger. The black hole at the center of the Milky Way galaxy, called Sagittarius A* (Sgr A*), has a mass equal to about 4.3 million suns. But even that pales compared to the heaviest black hole known: TON 618, found at the center of a quasar, weighs in at a staggering 66 billion solar masses.
Just how these giant black holes were formed remains a mystery even today. While one idea is that individual stellar-mass black holes combined, it is difficult to envision that there has been enough time since the Universe began 13.8 billion years ago for enough mergers to have occurred to account for the observed distribution of supermassive black holes. And it’s even harder to imagine that giant black holes formed early in the Universe.