Catalogs


Dozens of catalogs have been created by astronomers.  Each one is a tabulation of celestial objects, usually of a specific type, i.e., stars, nebulae, galaxies, etc.  Each entry contains an object identifier, celestial location coordinates, and varying amounts of technical data on the target object. The star maps in various atlases use alphanumeric acronyms which refer to these catalogs to label stars and other objects. The five catalogs summarized below are referenced in the Image Gallery on this website.

NAME PREFIX   DESCRIPTION
Messier M ENTRY COUNT Originally 45; later updates enlarged it to 110.
OBJECT TYPES Star clusters, nebulae and galaxies.
NOTES It is the oldest catalog and commonly used by amateur astronomers.
First published in 1771 by Charles Messier.
New
General
Catalog
NGC ENTRY COUNT Contains 7840 entries; includes Messier objects.
OBJECT TYPES Star clusters, nebulae and galaxies.
NOTES Used by professional and amateur astronomers.
First published in 1888 by John Dreyer.
It was revised in 1973 (RNGC) and in 1988 (NGC2000.0).
Index
Catalog
IC ENTRY COUNT Contains 5326 entries and is a supplement to the NGC.
OBJECT TYPES Star clusters, nebulae and galaxies.
NOTES Used by professional and amateur astronomers.
Henry
Draper
HD ENTRY COUNT Contains 359,083 entries.
OBJECT TYPES Stars within the Milky Way galaxy.
NOTES Used primarily by professionals.
First published between 1918 and 1924 with updates until 1949.
Barnard B ENTRY COUNT Contains 370 entries.
OBJECT TYPES Dark nebulae within the Milky Way galaxy.
NOTES Used by professional and amateur astronomers.
First published in 1913; updated in 1919.