Astronomers have known about a strange blue light coming from the heart of the Andromeda Galaxy (M31) for many years, but they were never sure exactly what it was. Thanks to new observations from Hubble, they now know it's a ring of young hot stars which are whipping around the supermassive black hole in the middle of M31. The 400 stars are packed into a disk only 1 light-year across, which is nestled inside a larger ring of older, redder stars. Our own Milky Way might have a similar phenomenon, which means this could be the situation in most galaxies.