Here is a bit more information on what they found.  The first spotting happened in 2015 like so many astronomical anomolies:

The discovery of the black hole was originally announced in July this year. It was observed with the NASA Hubble Space Telescope, in the Sloan Digital Sky Survey and then by ESA’s XMM-Newton and NASA’s Chandra X-ray Observatory.

Now follow-up observations by Benny Trakhtenbrot, from ETH Zurich’s Institute for Astronomy, and an international team of astrophysicists, using the 10 metre Keck telescope in Hawaii has thrown up some surprising results.

We’re looking forward to finding out more about this disruptive discovery.  And we will be posting details as they come in..

thanks to cosmosmagazine.com for the great info

thanks to M. Helfenbein, Yale University / OPAC for the pic