Recent observations by the Japanese XRISM spacecraft have shown that small black holes are not so “disciplined” when it comes to absorbing matter. Until now, it was known that supermassive black holes (which have a mass of millions of times that of the Sun) expel most of the matter they absorb. However, it has now been discovered that stellar-mass black holes, which are only a few times heavier than the Sun, exhibit the same behavior. The study studied the system 4U 1630-472, which is located about 26 thousand light-years from Earth. It consists of a sun-like star and a black hole that tears material from the star, forming a bright accretion disk.
