The "largest" cosmic explosion ever seen, according to astronomers, is a
fireball 100 times the size of our Solar System that abruptly started
burning in the furthest reaches of the cosmos more than three years
ago.
The scientists stressed that further research was necessary to fully
comprehend the perplexing occurrence even though they provided what they
believe to be the most plausible explanation for the explosion.
The explosion, known as AT2021lwx, is not the universe's brightest flash
ever seen. The brightest of all time gamma-ray burst, known as BOAT,
occurred in October and continues to hold the record.
The "largest" explosion, according to Philip Wiseman, an astronomer at the
University of Southampton in the United Kingdom and the
study's
principal author, was AT2021lwx since it released a lot more energy than
BOAT's tiny flash did in only three years.
Wiseman described it as a "accidental discovery" to AFP.
During an automated sky-scanning procedure in 2020, the Zwicky Transient
Facility in California discovered AT2021lwx for the first time.
However, "it basically sat in a database" until being discovered by people
the next year, according to Wiseman.
Astronomers, including Wiseman, didn't recognize what they had until they
observed it through more potent telescopes.
They calculated the explosion's distance to be about eight billion light
years by examining various light spectra.
The explosion behind it must be substantially larger because it is far
farther away than the majority of previous recent skybursts.
According to Wiseman, it is thought to be around two trillion times
brighter than the Sun.
Astronomers have investigated a number of potential reasons.
One of them is that AT2021lwx is an exploding star, however the explosion
is ten times brighter than any "supernova" that has been seen before.
A tidal disruption event, in which a star is shattered as it is drawn into
a supermassive black hole, is another possibility. However, Wiseman noted
that AT2021lwx is still three times as luminous as those events and that
their findings did not support this.
A quasar, which occurs when supermassive black holes eat enormous
quantities of gas at the heart of galaxies, is the only substantially
equivalent brilliant cosmic event.
However, according to Wiseman, they frequently fluctuate in brightness as
opposed to the AT2021lwx, which sprang up out of nowhere three years ago and
is still going strong today.
"This thing we have never, ever seen before - it just came out of nowhere,"
Wiseman said.
"Total puzzle"
The multinational research team outlined what they consider to be the most
plausible scenario in the new paper, which was published in the
Monthly Notices of the Royal Astronomical Society.
They postulate that a supermassive black hole is progressively engulfing a
vast, solitary cloud of gas that is around 5,000 times bigger than the
Sun.
Wiseman, though, asserted that "there is never certainty in science." To
determine whether their idea is "fully plausible," the team is working on
more simulations.
A potential issue is that supermassive black holes are located in the
centers of galaxies, which would be anticipated to be as large as the Milky
Way for an explosion of this scale, according to Wiseman.
However, nobody has been able to find a galaxy close to AT2021lwx.
"That's an absolute puzzle," Wiseman said.
Astronomers are scouring the skies to see whether any additional explosions
resembling this one have been overlooked now that they are aware of what to
look for.
