The Messier Catalogue is a list of astronomical objects made by French astronomer Charles Messier in 1771.[1] Messier was a comet hunter, and was annoyed by fuzzy objects which were not comets. He put together a list of these objects,[2] with his assistant Pierre Méchain.
The list uses numbers with an 'M' in front. Messier was limited by the objects he could see from France, so the list is incomplete by today's standards. It remains popular because people have used it for centuries and they are familiar with it.
The first edition covered 45 objects numbered M1 to M45. The total list published by Messier finally contained 103 objects, and the list was made up to 110 by modern astronomers working from Messier's notes..[3][4][5]
Other catalogues exist, most notably the New General Catalogue.