Astronomers have discovered the biggest cosmic explosion ever seen – and it lasted more than three years.
The explosion, known as AT2021lwx, is believed to be the result of a vast cloud of gas – thousands of times larger than the sun – being sent into a black hole after leaving its orbit.
Fragments of the cloud would have been swallowed up, creating a large dusty “doughnut” around the black hole.
Astronomers said such events are rare, but nothing on this scale has been observed before.
Dr Philip Wiseman, a researcher at the University of Southampton who led the search, said: “We came across this by chance as it was flagged by our search algorithm when we were looking for a type of supernova.
“Most supernova and tidal disturbance events last only a few months before fading away. For something to be bright for more than two years was immediately very unusual.”
Learn more:
Cosmic explosion could be the brightest ever
A ‘leaky’ black hole is tearing the universe apart
Scientists release new, sharper images of the supermassive black hole
According to the study, the actual explosion took place almost eight billion light-years away, when the universe was about six billion years old, and is still being detected by a network of telescopes.
AT2021lwx was first detected by the Zwicky Transient Facility in California in 2020 and later picked up by the Hawaii-based Asteroid Terrestrial-impact Last Alert System (ATLAS).
But until now, the extent of the explosion was not known.
Last year, astronomers witnessed the brightest explosion on record – a gamma-ray burst known as GRB 221009A.
Although it was brighter than the AT2021lwx, it only lasted a fraction of the time, meaning the overall energy released from the AT2021lwx’s explosion was far greater.
Dr Wiseman added that these events could be the key to understanding how the centers of galaxies change over time.
