Black Hole Seen 'Burping Out' Star 3 Years After Devouring the Cosmic Body

(Photo : Photo by NASA Via Getty Images)
Astronomers witnessed a mysterious event where a black hole is "burping out" the remains of the star it devoured three years prior.

Astronomers discovered a black hole that was "burping out" a star that it had devoured three years prior, spewing out spaghettified remains of the cosmic body.

The small star in question was ripped to shreds in October 2018 after it wandered too close to a black hole located in a galaxy 665 million light-years away from Earth. While the event might initially sound thrilling, it did not come as much of a surprise to astronomers who are occasional witnesses to these types of violent incidents while observing the night sky.

Burping Out a Star's Remains

However, after nearly three years of watching the star get massacred by the black hole, the same one is lighting up the skies once again. But now, it has not swallowed anything new, instead, spewed out the remains of its last meal.

A research associate at the Center for Astrophysics | Harvard & Smithsonian (CfA), Yvette Cendes, who is the lead author of a new study analyzing the recent phenomenon, said that the event caught the team completely by surprise. She noted that no one has ever seen a black hole do such a thing before, as per The Harvard Gazette.

The team that Cendes leads concluded that the black hole was now burping out material traveling at half of the speed of light. However, they are unsure why the incident was delayed by several years.

The study's results, which were described this week in the Astrophysical Journal, could help scientists better understand black holes' feeding behavior, which Cendes compared to burping after a meal. The astronomers discovered the unusual phenomenon while revisiting tidal disruption events (TDEs), which is when encroaching stars get spaghettified by black holes, that occurred over the last several years.

According to Live Science, scientists classified the event as AT2018hyz when it was observed that a star was engulfed by a black hole. Previously, black holes have been seen vomiting out remains of a star they are devouring, but the process usually happens simultaneously.

Mysterious Event

Astronomers consider black holes to be messy eaters who like to play with their food instead of outright devouring them. A black hole's consumption of a star, or TDE, is filled with powerful tidal forces that act upon the star from the black hole's immense gravitational force.

As the star is pulled ever closer to the black hole's maw, the tidal forces strip and stretch the star layer by layer, transforming the cosmic body into a long, noodle-like string that gets tightly wound around the black hole like spaghetti around a fork to form a ball of hot plasma in what is called spaghettification.

This plasma quickly accelerates around the black hole and spins out into an enormous jet of energy and matter. This then produces a distinctive bright flash that optical, X-ray, and radio-wave telescopes are able to detect and observe.

Scientists are now trying to determine the mystery behind why it took so long for this particular black hole to burp out the remains of its last meal. In a statement, an astronomy professor at Harvard University Edo Berger, who is a co-author of the study, said that this is the first time that experts have witnessed such a long delay between feeding and outflow, Space reported.