The biggest bang: Giant supernova smashes record as biggest, brightest explosion ever observed

There’s breaking a record, and then there’s blowing it to smithereens. Astronomers using relatively small telescopes around the globe have spotted the brightest supernova ever seen, shining about 20 times brighter than the 100 billion stars in the entire Milky Way galaxy — or, put another way, as bright as 570 billion suns.

The discovery of ASASSN-15lh, described in the journal Science, tests the limits of our understanding of the dramatic explosions that mark the deaths of powerful stars.

“This may be the most powerful supernova ever seen by anybody … it’s really pushing the envelope on what is possible,” said study co-author Krzysztof Stanek, an astronomer at Ohio State University.

Supernovae happen when a dying star explodes, sending loads of its supercharged stellar guts out into the surrounding universe. Depending on the type of supernova, different heavy elements, such as gold and other precious metals, are forged in these powerful explosions and spread throughout the cosmos, seeding other stars and their planets.

These dramatic events can sometimes shine even brighter than the galaxies that house them, typically lasting for several weeks before fading away. But this newly discovered supernova steals the spotlight — it’s at least twice as bright as the previous record holder, and it has lasted for several months. Compared to a typical supernova, ASASSN-15lh shines about 200 times brighter.

ASASSN-15lh was observed to have gone critical in May, but was first spotted in June of last year using the All Sky Automated Survey for Supernovae (ASAS-SN), based out of Ohio State University. The survey uses smaller telescopes to scan the sky every two to three days, searching for changes in the heavens. If some new bright object pops up, they’ll catch it, and astronomers can then use bigger telescopes to take a better look.