Discovered a new kind of black hole, able to Wake up and go to sleep

Astronomers from all over the world are constantly finding black holes in different galaxies, and often such an object may be a supermassive — millions of times heavier than the Sun. Black holes behave differently: they can gradually absorb the surrounding gas, or a star. And some how was able to suddenly “Wake up”, accelerating thus the rate of accretion, and then again to sleep.


Scientists from ETH Zurich have discovered a black hole — after her awakening, she increased the brightness of its galaxy by almost 50% in just two months. This fact became known after learning of the outbreak, first noticed in early 2017. Astronomers decided that between 2004 and 2017 there was a sharp increase of UV radiation AT flash 2017bgt. And it is not the break lights, which is sometimes observed in the absorption of stars by the black hole: this is evidenced by the slow evolution of the light curve and spectrum of features identified AT 2017bgt.

According to the researchers, they managed to open a new way to “power” of black holes. According to put forward the hypothesis that the outbreak was the result of accelerating the accretion of matter onto a supermassive black hole with a mass of about 1.8×107 solar. Other known methods of accelerating the growth of the black hole, as a rule, take much more time. In the past scientists were able to record only two events that proceeded the same way.

The galaxy in which has occurred a new phenomenon, is 900 million light-years from Earth. The black hole mass is 1.8×10-seventh the solar. By the way, the scientist is uncertain how these objects reach such impressive sizes.

Now astronomers say 75-fold increase in radiation in the ultraviolet range, the very same black hole again “hibernate” after 2017. However, the question of whether it was completely inactive prior to the outbreak remains open.

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