Astronomers announced Friday the discovery of the “biggest” cosmic explosion ever recorded, a ball of energy 100 times larger than our solar system that erupted suddenly three years ago, AFP reported.

Scientists have a new explanation for the cause of this phenomenon, but insist that more research is needed to clarify this aspect.

However, the event, named AT2021lwx, is not the brightest of all recorded. The “record” is held by the gamma-ray burst GRB221009A (a colossal burst of energy during the collapse of a star), discovered in October 2022 and considered the “brightest ever recorded.”

But the AT2021lwx explosion described in the log Monthly Notices of the Royal Astronomical Society According to the study’s lead author, Philip Wiseman, an astrophysicist at the University of Southampton in the UK, it can be called “the biggest” because it released infinitely more energy over three years than a gamma-ray burst.

AT2021lwx is the result of an “accidental discovery”, he told AFP. The explosion was recorded in 2020 automatically by the American Zwicky Transient Facility observatory in California. But that detection “remained unused in the observatory’s database,” according to Wiseman. Then scientists noticed it the following year. Direct observation of the phenomenon changed the situation. Analysis of the light showed that it took eight billion years to reach the telescope.

Astronomers are still wondering what caused this phenomenon. It could be a supernova, that is, the explosion of a massive star that has reached the end of its life, but the luminosity in the case of AT2021lwx is ten times greater than one would expect.

Another possibility is a tidal dismemberment event, where a star is torn apart by the gravitational forces of a black hole it has come too close to. But then again, the AT2021lwx is three times brighter to support such a scenario.

The only known equivalent of measured luminosity are quasars, galaxies at the center of which is a supermassive black hole that is saturated with matter and emits phenomenal amounts of light. But the light from quasars flickers, whereas in this case it suddenly brightened three years ago.

“I have never noticed anything like this (…). It seems to have appeared out of nowhere,” says researcher Philip Wiseman. However, as the research indicates, his team has an idea. Their theory is that a giant cloud of gas, the size of 5,000 suns, is being swallowed by a supermassive black hole.

Since the scientific principle is that “there are never certainties”, the team is working on new simulations using the available data to test how plausible this theory might be.

The problem is that supermassive black holes must be at the center of galaxies. And the one from the AT2021lwx event should be the size of our Milky Way. However, no one has yet discovered a galaxy in the vicinity of the observed event. “It’s a real mystery,” says Philip Wiseman.

Astronomers are left to search – in the sky and in databases with astral observations – similar events that could help clarify the explosion. (news.ro)