A list of celestial objects that might be mistaken for comets, compiled by the French comet-hunter C. J. Messier. His list first appeared in 1771, containing 45 objects; a revised list in 1780 added another 23 objects; and his final list, with 103 objects, appeared in 1781. Many of the objects were actually discovered by others, notably his compatriot Pierre François André Méchain (1744–1804). The objects catalogued by Messier include star clusters, nebulae, and galaxies. Astronomers still refer to these so-called Messier objects by their Messier, or M, numbers. Later observers have extended the catalogue beyond the 103 objects listed by Messier. (See Table 6, Appendix.)
Subjects: Astronomy and Astrophysics.