Caldwell catalogue

The Caldwell Catalogue is an astronomical catalog of 109 bright star clusters, nebulae, and galaxies for observation by amateur astronomers. The list was compiled by Patrick Caldwell-Moore as a complement to the Messier Catalogue.

The Messier Catalogue is used frequently by amateur astronomers as a list of interesting deep-sky objects for observations, but Moore noted that the list did not include many of the sky's brightest deep-sky objects, including the Hyades, the Double Cluster (NGC 869 and NGC 884), and NGC 253. Moreover, Moore observed that the Messier Catalogue, which was compiled based on observations in the Northern Hemisphere, excluded bright deep-sky objects visible in the Southern Hemisphere such as Omega Centauri, Centaurus A, the Jewel Box, and 47 Tucanae.cite book
last = O'Meara
first = Stephen James
title = The Caldwell Objects
publisher = Cambridge University Press
date = 2002
id = ISBN 0-521-82796-5] cite web
title=Caldwell Club Introduction
url=http://www.astroleague.org/al/obsclubs/caldwell/cldwl.html
accessdate=2006-09-08] He quickly compiled a list of 109 objects (to match the number of objects in the Messier Catalogue) and published it in Sky & Telescope in December 1995.cite journal
last = Moore
first = Patrick
title = Beyond Messier: The Caldwell Catalog
pages = 38
publisher = Sky & Telescope
date = December 1995
url = http://pqasb.pqarchiver.com/skyandtelescope/access/887305161.html?dids=887305161&FMT=CITE&FMTS=CITE&date=Dec+1995&author=Patrick+Moore&desc=Beyond+Messier%3A+The+Caldwell+Catalog
accessdate = 2006-08-29
format = subscription required]

Since its publication, the catalogue has grown in popularity and usage within the amateur astronomical community. However, the original list is criticized for some small compilation errors (listed below), and Moore may be criticized for what could be perceived as an egocentric-approach to compiling the list, including the use of one of his surnames to name the list and the use of "C" numbers to rename objects with more common designations.cite web
last = Ling
first = Alister
title = A Good Idea Gone Bad - Besides, Several Good Ideas Already Exist
url = http://members.aol.com/anonglxy/lingmoor.htm
accessdate = 2006-08-29]

As stated above, the list was compiled from objects already identified by professional astronomers and commonly observed by amateur astronomers. Unlike objects in the Messier catalogue, which are listed in the order they were discovered, the Caldwell catalogue is ordered by declination, with C1 being the most northerly and C109 being the most southerly, although two objects (NGC 4244 and the Hyades) are listed out of sequence. The original list also incorrectly identified S Norma Cluster (NGC 6087) as NGC 6067 and incorrectly labelled the Lambda Centauri Cluster (IC 2944) as the Gamma Centauri Cluster.

A natural progression for the amateur astronomer wishing to observe deep sky objects would be to view the Messier catalogue, followed by the Caldwell catalogue, and then the Herschel 400 Catalogue. At the end of this exercise the observer would have viewed nearly 600 objects. Although there are 618 objects listed in these three catalogues the Herschel 400 Catalogue does contain some objects from the Messier and Caldwell catalogues.

Caldwell Star Chart

Number of objects by type in the Caldwell catalogue.

11-20

41-50

71-80

101-109

References

ee also

* Messier Catalogue
* Herschel 400 Catalogue
* New General Catalogue (NGC)
* Index Catalogue (IC)
* Revised New General Catalogue (RNGC)
* Revised Index Catalogue (RIC)

External links

* [http://www.seds.org/messier/xtra/similar/caldwell.html The Caldwell Catalogue at SEDS]
* [http://www.astroleague.org/al/obsclubs/caldwell/cldwl.html The Caldwell Club]
* [http://www.ngc891.com/modules.php?op=modload&name=Stars&file=constellation&catalogue=Caldwell Caldwell Star Charts, Images and more]
* [http://www.12dstring.me.uk/caldwellcatalogue.htm Searchable Caldwell Catalogue list]
* [http://www.space-and-telescope.com/CaldwellObjects.aspx Clickable Caldwell Object table]