Black holes make up a set of cosmic objects, one of the most mysterious in the universe. Scientists theorize about their existence for a hundred years, and some indirect evidence of them had already been detected; until in early 2019 we got the first image of one of them. The photograph represents the event horizon of the black hole at the center of the galaxy M87, 55 million light-years from home, in what was one of the greatest milestones in recent science.
As we pointed out, the details of the structure of a black hole were calculated from Albert Einstein’s Theory of General Relativity. What we call the singularity constitutes the center of a black hole, and is hidden by the ‘surface’ of the object, the event horizon. Within the event horizon, the escape velocity (that is, the speed required for matter to escape from the gravitational field of a cosmic object) exceeds the speed of light, sonot even rays of light can escape.
Only the most massive stars, at least three times the size of our Sun, become black holes at the end of their lives. Stars with a lower amount of mass, like ours, evolve into other types of bodies, such as white dwarfs or neutron stars.
As of September 2, 2020, two studies have just been published (inPhysical Review LettersYAstrophysical Journal Letters) that described the detection of the most massive black hole that has been detected with gravitational waves. The research team detected the merger of two black holes, but one of the two was much more massive than any other observed in such a collision. The researchers believe that the heavier of the two may be the result of a previous merger between two black holes.
Black holes are fascinating objects that, in turn, raise many questions. In this gallery, we delve into the knowledge of black holes.
