Messier object
From Wikipedia, the free encyclopedia
The Messier objects are a set of astronomical objects first listed by French astronomer Charles Messier in his "Catalogue des Nébuleuses et des Amas d'Étoiles" ("Catalogue of Nebulae and Star Clusters") included in the Connaissance des Temps for 1774 (published in 1771). The original motivation of the catalogue was that Messier was a comet hunter, and was frustrated by objects which resembled but were not comets. He therefore compiled a list of these objects.[1]
The first edition covered 45 objects numbered M1 to M45. The total list consists of 110 objects, ranging from M1 to M110. M102 cannot be positively identified; likely candidates are the galaxies M101 and NGC 5866.
Messier's final catalogue was included in the Connaissance des Temps for 1784 (published in 1781). Many of these objects are still known by their Messier number.[2]
Because Messier lived and did his astronomical work in France in the Northern Hemisphere, the list he compiled contains only objects from the north celestial pole to a celestial latitude of about –35°. Many impressive Southern objects, such as the Large and Small Magellanic Clouds are excluded from the list. Because all of the Messier objects are visible with binoculars or small telescopes (under favorable conditions), they are popular viewing objects for amateur astronomers. In early spring, astronomers sometimes gather for "Messier marathons", when all of the objects can be viewed over a single night.[3]
[edit] See also
- List of Messier objects
- Messier marathon
- Category:Messier objects
- Deep sky object
- New General Catalogue
- Herschel 400 Catalogue
- Caldwell catalogue
[edit] References
- ^ SEDS Messier Database. THE MESSIER CATALOG. Retrieved on 2007-11-10.
- ^ Original Messier Catalog of 1781. Original Messier Catalog of 1781. Retrieved on 2007-11-10.
- ^ The Messier Marathon. THE MESSIER MARATHON. Retrieved on 2007-11-10.