The Andromeda Galaxy (aka Messier 31) has several satellite galaxies. The best known are M32 and M110. M32 probably underwent a close encounter with Andromeda Galaxy and had its stellar disk removed by M31. That encounter caused a sharp increase of star formation in M32’s core region. M32 is the large galaxy near the center of the image.
M110 is the smaller galaxy below and to the right of MN32. It also appears to be interacting with the Andromeda Galaxy. Astronomers have found in the large galaxy’s halo a stream of metal-rich stars that appear to have been stripped from the satellite galaxies.
Image Credit: Torben Hansen, CC BY 2.0