Scientists have discovered the brightest ever supernova.

The supernova, dubbed SN2016aps, is the brightest, most energetic and likely most massive supernova that has ever taken place, according to the Harvard and Smithsonian Center for Astrophysics (CfA) in Cambridge, Mass.

A paper on the research has been published in the journal Nature Astronomy.

“SN2016aps is spectacular in several ways,” said Edo Berger, Harvard University professor and co-author on the paper, in a statement. “Not only is it brighter than any other supernova we’ve ever seen, but it has several properties and features that make it rare in comparison to other explosions of stars in the universe.”

A supernova, or the explosion of a star, is the largest explosion that takes place in space, according to NASA.

SN2016aps outshone normal supernova explosions by 500 times, the researchers said. “The intense energy output of this supernova pointed to an incredibly massive star progenitor,” explained Berger in the statement. “At birth, this star was at least 100 times the mass of our Sun.”

The supernova was first spotted in 2016 by scientists from CfA, the UK’s University of Birmingham, Northwestern University and Ohio University, using information from the Panoramic Survey Telescopes and Rapid Response System (Pan-STARRS).

“We determined that in the final years before it exploded, the star shed a massive shell of gas as it violently pulsated,” said Matt Nicholl, lecturer in gravitational wave astronomy at the University of Birmingham and study lead author, in the statement. “The collision of the explosion debris with this massive shell led to the incredible brightness of the supernova. It essentially added fuel to the fire.”

Scientists were also surprised by the high levels of hydrogen gas in SN2016aps.

“That SN2016aps held onto its hydrogen prompted us to theorize that two less massive stars had merged together since lower mass stars hold onto their hydrogen for longer,” said Berger. “The new star, borne of the merger, was heavy with hydrogen and also high enough in mass to trigger pair-instability.”