A small irregular galaxy thought to orbit the Milky Way, trailing stars behind it to create a structure known as the Monoceros Ring. It should be noted that there is some dispute over the nature of the galaxy, but if current analysis proves to be correct, then this is the closest known external galaxy to the Solar System.
The Canis Major Dwarf Galaxy is not directly visible here, but this image does show the approximate location and extent of the dwarf galaxy within southern Canis Major. Imagery provided by Aladin sky atlas
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