Messier Catalog

The Messier Catalog (or list of Messier Objects or Catalogue des Nebuleuses et des Amas d'Etoiles, i.e., Catalogue of Nebulae and Star Clusters) is Charles Messier's 1771 catalog of fixed but apparently-non-stellar astronomical objects, almost all now known to be galaxies. Messier was interested in finding comets and produced this list of objects that look something like comets (extended and fuzzy) but had been established to be something else. The objects are now commonly designated by M with a number (examples: Andromeda (M31), Triangulum Galaxy (M33), M82, M87) and include galaxies, clouds, and stellar clusters. The objects are number 1 through 110, the last seven being objects Messier did not include in his list, but are mentioned in his notes. They are among the most prominent extended sources in the sky and their Messier designations are still commonly used by astronomers. Since the list dates from a time when telescopes were less capable, amateur astronomers find it a convenient list of galaxies and other such objects to view.

The New General Catalogue (NGC) began as a similar list created by William Herschel, which listed substantially more objects and later underwent further expansion.