NGC 6388
NGC 6388 is a globular cluster located in the Milky Way towards the constellation Scorpius. While only middle aged in terms of globular clusters, NGC 6388 is still over 10 billion years old. It is thought to possibly contain an intermediate black hole at its center.
Optical observations suggested the possibility of a central black hole, and at one point X-ray observations were thought to be related. However, further observations showed that the X-rays did not originate from the black hole, but rather a broken planet being destroyed by a white dwarf star. When a planet drifts to close to a white dwarf, the tidal forces rip it apart. As the pieces fall in to the star, they heat up and release X-rays.
Image from ESA, information from Chandra.













