With the help of AI, a US astronomer has found the particularly extreme case of a supermassive black hole tearing apart a star. The find is downright “absurd,” he says, because the object, which can only be seen temporarily (“transient” in astronomy), is not only a thousand times brighter than a supernova, but has also lasted for 800 days. Precisely because it does not match previous discoveries at all, the object was overlooked for so long. Because computers, like the one used here, could only easily find objects that have been precisely described to them. For “ZTF20abrbeie” there is no role model.
Exceptional in every way
The object, nicknamed “Scary Barbie”, was observed for the first time in 2020, but only now has its unusual nature been explored. Explorer Danny Milisavljevic explainsthat it is the most energetic phenomenon he has ever encountered. He and his team therefore assume that it is a matter of so-called spaghetti. An object is literally stretched out by the immense mass of a black hole. In this case, however, a particularly massive black hole and a particularly large star are involved, and it also takes an immensely long time.
“Everything is so unusual, the characteristics are just frightening,” says Milisavljevic. At the same time, the available data would suggest that the process is far from over, and the object will probably shine as brightly for years to come. But that is also due to the immense distance, because the light is stretched so much on the way to earth that the event appears to us to be twice as long as it actually lasts. Such discoveries would show us that there are still mysteries and wonders to be discovered in space, things no one has seen before, the astronomer says.
He discovered the anomaly using an AI technique, the “Recommender Engine For Intelligent Transient Tracking” (REFITT). In the pictures taken by telescopes from all over the world, she looks for objects that are temporarily visible, such as exploding stars. Such objects are usually only visible for hours or days, with a duration of more than two years being extremely unusual. The fact that “ZTF20abrbeie” was overlooked for so long is precisely due to these unusual properties and the fact that the object appeared in a “somewhat neglected region of the sky”. It is now being researched further. The find is presented soon in the Astrophysical Journal Letters.
(mho)