Caldwell number

Caldwell number

[′kȯl‚dwel ¦nəm·bər]
(astronomy)
A number by which star clusters, nebulae, and galaxies are listed in the Caldwell Catalog, arranged in order of declination; for example, the Hyades are C41.
References in periodicals archive ?
Deep-sky selections are dutifully labeled with Messier and Caldwell numbers, but the catalogs themselves await introduction in an appendix.