Astronomers find a new type of cosmic explosion

Image credit: Getty/Oliver Burston
Date:17 November 2017 Tags:, ,

It could be a supernova, or a black hole shredding a star, but this cosmic explosion sure is massive.

By Avery Thompson

The universe is filled with gigantic, world-shattering explosions. Entire stars can explode in spectacular supernovas, black holes can output huge amounts of energy in the form of gamma ray bursts, and black holes and neutron stars can collide with enough force to shake the very fabric of spacetime millions of light-years away.

Given the sheer number of different explosions, it shouldn’t be surprising that there are still some we’re just discovering. Recently, a group of astronomers did just that, identifying a new type of explosion in a distant galaxy.

The explosion, called PS1-10adi, took place in a galaxy 2.4 billion light-years away and was picked up by telescopes in Hawaii and La Palma. This explosion was measured to be bigger than a supernova, which means there are two possible explanations: either it’s a supernova that outclasses all others, or it’s a star getting eaten by a supermassive black hole.

Both of these possibilities are similar to explosions we’ve already seen before, but the scale of this particular one leads scientists to believe something unique is happening. In either case, it’s likely that the extreme size of the explosion is the result of being located close to the centre of its galaxy.

“If they are supernova explosions then their properties are more extreme than we have ever observed before, and are likely connected to the central environments of the host galaxies,” says lead study author Erkki Kankare. “If these explosions are tidal disruption events–where a star gets sufficiently close to a supermassive black hole’s event horizon and is shredded by the strong gravitational forces – then its properties are such that it would be a brand new type of tidal disruption event.”

Studying this particular explosion could tell us more about similar explosions that astronomers have been picking up all over the universe. Until now, these explosions have been mysteries, but with this new discovery we’ve finally narrowed down what’s causing them. The one thing they all have in common is a location in the centre of large galaxies, and understanding these explosions could tell us more about galaxy centres.

“[These explosions’] existence provides us with important information about the extreme environment in the central, hidden, part of galaxies,” says study author Cosimo Inserra. Maybe someday we’ll figure them all the way out.

From: PM USA