The galaxy is located 10.7 billion light years away from Earth, and previously had seemed relatively unremarkable until October 2014 where out of the blue it became 1000 times brighter.
The mysterious explosion only lasted a few hours, and left astronomers completely puzzled.
“We may have observed a completely new type of cataclysmic event,” said researcher Kevin Schawinski from the Swiss Federal Institute of Technology in Zurich.
“Whatever it is, a lot more observations are needed to work out what we’re seeing.”
Astronomers say that a possibility could be that the event was a gamma ray burst, a high energy explosion usually caused by a large star collapsing, or a merger of 2 neutron stars. These gamma ray bursts are usually picked up by our instruments when they are pointed toward Earth, however if one was pointing away, it may explain the new explosion.
Another mentioned possibility is that it was caused by a white dwarf star being shredded by a black hole.
“None of these ideas fits the data perfectly,” said researcher Ezequiel Treister.
“But then again, we’ve rarely if ever seen any of the proposed possibilities in actual data, so we don’t understand them well at all.”