Billions of light years away, there is a giant ball of hot gas that is brighter than hundreds of billions of suns. It is hard to imagine something so bright. So what is it? Astronomers are not really sure, but they have a couple theories.
They think it may be a very rare type of supernova — called a magnetar — but one so powerful that it pushes the energy limits of physics, or in other words, the most powerful supernova ever seen as of today.
This object is so luminous that astronomers are having a really difficult time finding a way to describe it. “If it really is a magnetar, it’s as if nature took everything we know about magnetars and turned it up to 11,” said Krzysztof Stanek, professor of astronomy at Ohio State University and the team’s co-principal investigator, comedically implying it is off the charts on a scale of 1 to 10.The object was first spotted by the All Sky Automated Survey of Supernovae (ASAS-SN or “assassin”), which is a small network of telescopes used to detect bright objects in the universe. Although this object is ridiculously bright, it still can’t be seen by the naked eye because it is 3.8 billion light years away.
ASAS-SN, since it began in 2014, has discovered nearly 250 supernovae, however this discovery, ASASSN-15lh, stands out because of its sheer magnitude. It is 200 times more powerful than the average supernova, 570 billion times brighter than the sun, and 20 times brighter than all the stars in the Milky Way Galaxy combined.
“We have to ask, how is that even possible?” said Stanek. “It takes a lot of energy to shine that bright, and that energy has to come from somewhere.”