Astronomers they are believed to have discovered the largest cosmic explosion ever detected.

According to a BBC report the explosion is more than 10 times brighter than any recorded star that has exploded – known as supernova.

So far it has lasted more than three years, much longer than most supernovae which are usually only visibly bright for a few months.

One theory is that the explosion was caused when a huge cloud of gas was swallowed by a black hole.

A flash in the sky was first automatically detected and recorded in 2020 by the Zwicky Transient Facility in California. But only a year later, the astronomers dealing with this data picked it up.

They named the event AT2021lwx. At the time they thought it was unremarkable because there was no indication of how far away it was and therefore its brightness could not be calculated.

Last year, a team led by Dr Philip Wiseman from the University of Southampton analyzed the light from the event which allowed them to calculate its distance – 8 billion light years away. Dr. Wiseman described the moment he processed the brightness of the phenomenon.

“We thought, ‘Oh my God, this is outrageous!'”

The team was completely baffled as to what could have caused something so brilliant. There was nothing in the scientific literature that could explain something so bright lasting so long, according to Dr. Wiseman.

“Most supernovae and tidal disruption events only last a few months before they die out. For something to be bright for two-plus years was immediately very unusual.”

His theory is that the explosion is the result of a huge cloud of gas, possibly thousands of times larger than our Sun, being swallowed by a supermassive black hole.

This would send shock waves into space and leave superheated remnants of the cloud surrounding the black hole like a giant donut ring.

All galaxies are believed to have giant black holes at their heart. Dr Wiseman believes such powerful explosions could play an important role in what he describes as “sculpting” the center of galaxies.

“Could these events, although extremely rare, be so energetic that they are key processes in how galaxy centers change over time.”

The search is now on for more massive explosions like this one, according to Dr Robert Massey, who is the Deputy Chief Executive of the Royal Astronomical Society.

“We’ve never seen anything like this before and certainly not on this scale,” he told BBC News.

“I would be surprised if this is the only object like it in the Universe.”

Dr. Wiseman hopes to detect more events like this with new telescope systems coming out in the coming years.

The team is now preparing to collect more data on the explosion – observing the object at different wavelengths, including X-rays, which could reveal the temperature of the object and what processes may be taking place on the surface. They will also run upgraded computer simulations to check if they match their theory of what caused the explosion.

Last year, astronomers spotted the brightest burst on record, a gamma-ray burst known as GRB 221009A, which lasted just over ten hours. Although this was brighter than AT2021lwx, it only lasted for a fraction of the time, meaning that the explosive power of the AT2021lwx burst was much greater.