In October 2018, scientists observed a black hole literally torn apart and swallowed a small star in a galaxy 665 million light years away from the Earth. Although the event itself was considered to be very ordinary, its consequences became unusual. Almost three years after the event, the black hole suddenly returned part of the absorbed matter.
According to the Harvard-Smitson Center for Astrophysics, although the return of a portion of the black holeed matter occurs regularly, it happens almost immediately and never — a few years after the event.
The discovery was made when a team of scientists re-inspected the "emerging events" that took place in the event of the absorption of the stars with black holes in the last few years, and it turned out that one of the black holes mysteriously "reanied" in June 2021.
A more detailed study using a number of telescopes showed that after TDE, which received the code name AT2018hyz, a black hole that had remained completely silent for several years, suddenly became one of the most powerful sources of radiation in the radio band. In other words, scientists at all noticed for the first time the return of matter from a black hole almost three years later.
It is known that there is a lot of light in TDE. Gravity near a black hole usually "spaghettitifys" the star by literally tearing it apart. However, stretched spirals around black holes can occur millions of light years from the scene. Some of the matter sometimes returns.
"Failed" matter in the case described travels at an enormous speed of 50% of the speed of light. By comparison, after most TDE matter can return 10% of the speed of light. The next step for scientists is to study a new discovery in detail. This may happen quite often, and scientists simply did not know how to keep an eye on black holes after they absorbed the stars over a long period of time.