Here is more in depth info on their surprising find:

The measurements were so different, the survey’s automated software didn’t even recognize it as a supernova, Dong wrote in an email to Discovery News.

“We thought about various non-supernova, exotic scenarios, but none seemed to work,” Dong said.

The supernova’s host galaxy itself presents another puzzle. Most superluminous supernovae are found in small, dwarf galaxy where lots of stars are forming. ASASSN-15lh, in contrast, appears to be in a large, but relatively quiescent galaxy about three times more massive than the Milky Way.

Apparently they said this one is so bright that it will be easy to get observations of this awesome thing.

Check back for updates as they come in.

thanks to discovery.com for the great info

thanks to hubble heritage for the pic of a remnant supernova in the magellanic cloud