Hubble Space Telescope (HST) image of a black hole and galaxies. The location of an intermediate-mass black hole is indicated by the white circle. The black hole is much smaller than supermassive black holes found in the centres of galaxies. The black hole, named 3XMM J215022.4?055108 was first identified by an X-ray burst emitted by hot gas from a star as it was captured and destroyed by the black hole. The black hole is inside a dense cluster of stars in the vicinity of the galaxy at the centre. Much smaller-looking background galaxies are also seen, including a face-on spiral just above the central foreground galaxy. Image obtained by Hubble's Advanced Camera for Surveys.