Messier numberSee Messier Catalog.
Collins Dictionary of Astronomy © Market House Books Ltd, 2006
Messier number[me′syā ‚nəm·bər]
A number by which star clusters and nebulae are listed in Messier's catalog; for example, the Andromeda Galaxy is M 31.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.