The Messier Catalogue is a list of astronomical objects made by French astronomer Charles Messier in 1771. Messier was a comet hunter, and was annoyed by objects which were not comets. He put together a list of these objects, along with his assistant Pierre Méchain.
The objects have 'M' in front. He was limited by the objects he could see from France so the list is incomplete by today's standards but it remains popular due to the length of time it has been around and astronomers' familiarity with these objects.
The first edition covered 45 objects numbered M1 to M45. The total list published by Messier finally contained 103 objects, but the list "got an independent life" with changes by other astronomers. The first change came from Camille Flammarion in 1921, who added Messier 104 after finding Messier’s side note in his 1781 edition of the catalogue. M105 to M107 were added by Helen Sawyer Hogg in 1947, M108 and M109 by Owen Gingerich in 1960, and M110 by Kenneth Glyn Jones. M102 was observed by Méchain, who gave his notes to Messier; later, Méchain himself said that this object does not exist, and it was simply a re-observation of M101. Some sources mention the galaxy NGC 5866 for M102, but its description does not fit with Méchain's notes.
Other catalogues exist, most notably the New General Catalogue.
In springtime some astronomers conduct Messier Marathons where they try to locate as many of these objects in one night as possible.
- "Charles Messier's Catalog of Nebulae and Star Clusters". SEDS. 15 June 2007. http://seds.org/messier/xtra/history/m-cat.html. Retrieved 2010-05-08.
- "The Messier Catalog". SEDS Messier Database. SEDS. 25 February 2008. http://seds.org/messier/. Retrieved 2010-05-08.
- Patrick Moore (1979). The Guinness Book of Astronomy. Guinness Superlatives. ISBN 09-00-42476-1.
- Charles Messier (1781). "Catalogue des Nébuleuses & des amas d'Étoiles". Connaissance des Temps for 1784. pp. 227–267. Bibcode 1781CdT..1784..227M.
- "Original Messier Catalog of 1781". Original Messier Catalog of 1781. SEDS. http://seds.org/messier/xtra/Mcat/mcat1781.html#messier1781. Retrieved 2010-05-08.