Astronomers spot largest cosmic explosion ever seen

Astronomers have captured the largest cosmic explosion ever witnessed — a fireball 10 times brighter than any known supernova.

The explosion, known as AT2021lwx, has been blazing for three years and is believed to have been triggered by a giant cloud of gas being consumed by a supermassive black hole.

WATCH THE VIDEO ABOVE: SpaceX rocket explodes minutes after takeoff.

Watch the latest News on Channel 7 or stream for free on 7plus >>

Astronomers are still in the dark about the phenomenon and say more research is needed to properly understand it.

A new study, which argued the gas cloud as the likely explanation, says the “extraordinary event” was stumbled upon by chance.

University of Southampton research fellow Dr Philip Wiseman, who led the observations, said the flare-up was initially spotted in 2020.

While most supernovae events only last for a couple of months before fading, AT2021lwx gradually got brighter.

It was only when astronomers looked at it in follow-up observations did they realise its scale.

“For something to be bright for two-plus years was immediately very unusual,” Wiseman told Forbes.

Wiseman told The Guardian his team of researchers estimate the explosion is a “fireball 100 times the size of the solar system with a brightness about two trillion times the sun”.

“In three years, this event has released about 100 times as much energy as the sun will in its 10 billion-year lifetime.”

The study, published on Friday in the Monthly Notices of the Royal Astronomical Society, suggests the most likely cause of AT2021lwx is a vast cloud of gas, thousands of times bigger than the sun, being sent into the black hole after coming off its orbit.

Wiseman and his team believe the black hole swallowing the gas has sent shockwaves into the leftover gas and the doughnut-shaped dust surrounding it, causing them to emit bright electromagnetic radiation.

While no events have been witnessed on this scale before, AT2021lwx, which was roughly eight billion light years away, is not the brightest of all time.

That title is held by a gamma-ray burst, known as GRB 221009A, that was spotted in October.

The burst only last minutes, while the new phenomenon continues, meaning the energy of AT2021lwx is much greater.