Scientists measure the largest cosmic explosion ever

By chance, astronomers have discovered the largest explosion ever seen in the universe. It is believed to have been caused by a black hole that swallowed a giant cloud of dust.

While British astronomers were looking for exploding stars, the so-called supernovae, they discovered a gigantic cosmic explosion. The light released is 10 times brighter than a supernova and three times brighter than the most luminous Tidal disturbance has occurred (TDE), where a single star is swallowed up Giant black hole. Astronomers from the University of Southampton (UK) share their discovery in the Scientific Journal Monthly Notices of the Royal Astronomical Society.

Long blast

The explosion, dubbed AT2021lwx, appeared by accident. Astronomers were actually looking for supernovae and used a search algorithm: It characterized the cosmic event. But it soon became clear that AT2021lwx was no ordinary supernova. The explosion lasted about three years, while most supernovae and TDEs only last a few months before fading away.

By analyzing the different wavelengths in the emitted light, astronomers were able to calculate the distance to AT2021lwx. The explosion occurred about 8 billion light-years away: the universe was then about 6 billion years old (now it is 13.7 billion years).

“This is unprecedented.”

“Once you know the distance to the object and how bright it is from Earth, you can also calculate the brightness of the object itself,” Sebastian Honig, one of the study’s authors, said in a press release. “Once we did these calculations, we realized that this is a very ferocious thing to do.”

The only things in the universe are as bright as the AT2021lwx Quasars – supermassive black holes into which a continuous stream of gas falls at high speed. “If we study a quasar for a longer period of time, we see the brightness fluctuate,” said Mark Sullivan, an author of the paper. “But if we look at observations from the past ten years, we don’t see AT2021lwx yet. It will appear suddenly only in 2020 and then it will be as bright as the brightest objects in the universe, which is unprecedented.”

Even brighter

The cause of the explosion is still a bit of a guess. But the Southampton team suspects that a very large cloud of gas or dust – perhaps thousands of times more massive than the Sun – has slipped out of orbit around a black hole and violently sank into it.

Astronomers will now collect more data about the explosion. For example, they want to measure with x-rays, which they can use to calculate body temperature. They also want to use improved computer simulations to test whether it matches their theory of cause.

The AT2021lwx isn’t the brightest explosion yet. Last year, astronomers saw a gaMemflash, known as GRB 221009A, which was much brighter. But the flash lasted far too short, with the AT2021lwx firing more power in total.