By Ethan Percival
First detected in November of 2020, astronomers have found what is currently the largest cosmic explosion ever seen, with a brightness level ten times greater than a supernova and 2 trillion times brighter than the sun. While normal supernovas only remain bright for a few months, this explosion, named AT2021lwx, has persisted for three years.
It has been calculated that the explosion occurred 8-billion light years away from Earth, nearly 7 billion years ago with the light from the explosion only just now reaching us. Scientists theorize that the explosion was caused by a supermassive black hole colliding with a hydrogen cloud, thousands of times bigger than our sun. As the black hole devoured the cloud, the resulting shockwave caused a fireball 100 times larger than our solar system.
This explosion was likely the one of the largest explosions ever recorded. For reference, the blast released 100 times more energy than the sun will ever produce in its 10 billion year existence.
Researchers at Zwicky Transient Facility were the first to spot the explosion, with the Asteroid Terrestrial-impact Last Alert System in Hawaii spotting the event a few months later, though the sheer size of it would not become clear until follow-up investigations were made. “We came upon this by chance, as it was flagged by our search algorithm when we were searching for a type of supernova,” said Dr. Philip Wiseman, a lead researcher at the University of Southampton in England. “It went unnoticed for a year as it gradually got brighter… When I told our team the numbers they were all just so shocked.”
The findings on this historic cosmic event can be found here, at Monthly Notices of the Royal Astronomical Society.