Credit: X-ray (NASA/CXC/SAO/Li et al.),

The large image here shows an optical view, with the Digitized Sky Survey, of the Andromeda Galaxy, otherwise known as M31. The inset shows Chandra images of a small region in the center of Andromeda. The image on the left shows a sum of Chandra images taken before January 2006 and the image on the right shows a sum of images taken after January 2006. Before 2006, three X-ray sources are clearly visible, including one faint source close to the center of the image. After 2006, a fourth source, called M31*, appears just below and to the right of the central source, produced by material falling onto the supermassive black hole in M31.

Provider: Chandra X-ray Observatory

Image Source: http://chandra.harvard.edu/photo/2010/m31/

Curator: Chandra X-ray Observatory, Cambridge, MA, USA

Image Use Policy: http://chandra.harvard.edu/photo/image_use.html