black hole, an anomalous region of space-time, is not able to leave even light, so it is physically impossible to see it. However, astronomers can still detect the moment when some passing star is too close to the black hole, after which it will absorb it, turning it into accretion diskshining like an entire galaxy.
The brightness of these disks is constantly changing: the surroundings of the hole “flicker”, although for a long time no one could say why. To answer this question, a group of astronomers from Australia and the United States spent five years observing more than five thousand of the most “greedy” black holes in the starry sky.
At the center of our Milky Way is also supermassive black hole, whose mass is four million times that of the sun, but it behaves relatively “decently”, and about 200 billion stars, including our star, safely revolve around this hole. However, not all galaxies are as peaceful, and, for example, when two galaxies approach each other, gravitational forces can force individual stars to come too close to the black hole, after which it tears them apart and absorbs them. The “appetite” of some holes is amazing: in 2018 there was described A black hole capable of swallowing our Sun in just 48 hours.
However, scientists still know quite a bit about the behavior of black holes when they gobble up a dying star, and five years of observations of the most active black holes have revealed daily measurements of the brightness of their accretion disks. It turned out that the flickering of the disk is a kind of turbulence in a superdense, uncontrolled environment, under the influence of intense gravitational and magnetic fields, where space itself is bent to the limit. Back in 1998, astronomers suggested explanation of this phenomenon, calling it “magnetic-rotational instability”, but it took years of observations and correction of the constructed models, taking into account the size of the black hole and the speed of rotation of the accretion disk, so that the flickering patterns in the vicinity of various holes acquired a similar look.
Now scientists plan to understand the nature of subtle differences between the accretion disks of different black holes, because it is quite possible that some of them arose simply because we observe different objects from different angles. In this case, additional correction for position in space will allow us to build an accurate model of the “feeding” of the black hole and learn even more about these mysterious cosmic anomalies.
Study published In the magazine Nature Astronomy.
