Charles Messier first discovered M54 in 1778, but it wasn't until 1994 that astronomers found it didn't belong to the Milky Way. Rather, it is the surviving core of the Sagittarius dwarf galaxy.

A ndromeda III is one of at least 13 dwarf satellite galaxies in orbit around the Andromeda galaxy, or Messier 31, the Milky ...

SagDEG: Located roughly 90,000 light years from Earth, the Sagittarius Dwarf Elliptical Galaxy (SagDEG) or Messier 54 is a satellite galaxy of the Milky Way which is predicted to become a part of ...