…it’s a photobomb by an AGN with a possible supermassive black hole binary!
A new paper on research led by Trevor Dorn-Wallenstein, a graduate research student working with me at UW, has recently been published by ApJ and featured in a press release from the Chandra X-ray Observatory and the University of Washington. While searching for unusual massive stars in M31, we wound up serendipitously discovering a background galaxy with a lightcurve that suggests it might contain two supermassive black holes in a closely-orbiting binary!
Check out the paper, press release, and Trevor’s guest post on the Chandra X-ray Observatory blog to read more about the discovery.