What's 10 times brighter than the largest recorded supernova? Turns out scientists aren't sure—but they've recently discovered a "massive outburst" in a galaxy 44 million light-years from Earth.

"It's a very rare event," says Robert Minchin, who presented his findings at the American Astronomical Society's meeting in California Monday. "I don't know of anything exactly the same or very similar to this being seen before."

The energy outburst, or "belch" first showed up on the team's radar in 2008 and increased in power as they observed it during 2010 and 2011. The team lucked into the discovery—they were observing the galaxy known as NGC 660 (a galaxy found on the constellation Pisces) when they noticed the burst.

"We found that one galaxy had changed over [a few years] from being placid and quiescent, to undergoing a hugely energetic outburst at the end," Minchin says. The team believes the energy is coming from a black hole in the center of that galaxy.

They are continuing to monitor the burst, which is still ongoing, in order to find out exactly what's causing it.

Minchin's team had two theories as to what may have caused the burst: They believed it may have been a supernova—or exploding star—that was much more powerful than anything ever seen before, or a "jet" of superfast material being sucked into a black hole. What they found was not one, but several jets.

"It was something more complicated than that—it looks like a jet that is projecting material in the path of a cone," he says. "What's amazing is we caught this by complete chance. We're going to watch it to see how it develops."