Editing Uppsala General Catalogue

{{Short description|Catalogue of galaxies visible from the northern hemisphere}}
The '''[[Uppsala]] General Catalogue of Galaxies''' ('''UGC''') is a catalogue of 12,921 [[galaxy|galaxies]] visible from the northern hemisphere. It was first published in 1973.<ref>{{Cite news
 | title=The Uppsala General Catalogue of Galaxies
 | author=Peter Nilson
 | url=http://nedwww.ipac.caltech.edu/level5/March02/Nilson/Nilson_contents.html
 | access-date=2011-01-30}}</ref>
[[File:A slashing smudge across the sky.jpg|thumb|Dwarf galaxy [[UGC 1281]].<ref>{{cite web|title=A slashing smudge across the sky|url=http://www.spacetelescope.org/images/potw1447a/|website=www.spacetelescope.org|publisher=ESA/Hubble|access-date=2 December 2014}}</ref>]]
The catalogue includes essentially all galaxies north of [[declination]] −02°30′ and to a limiting diameter of 1.0 [[arcminute]] or to a limiting [[apparent magnitude]] of 14.5. The primary source of data is the blue prints of the [[Palomar Observatory Sky Survey]] (POSS). It also includes galaxies smaller than 1.0 [[arcminute]] in diameter but brighter than 14.5 magnitude from the [[Catalogue of Galaxies and of Clusters of Galaxies]] (CGCG).

The catalogue contains descriptions of the galaxies and their surrounding areas, plus conventional system classifications and position angles for flattened galaxies. Galaxy diameters are included and the classifications and descriptions are given in such a way as to provide as accurate an account as possible of the appearance of the galaxies on the prints. The accuracy of coordinates is only what is necessary for identifications purposes. The catalogue was edited by [[Peter Nilson]], at the time Doctor of Astronomy and a researcher at Uppsala, who had already published some essays about the history of his science; a couple of years later he left his career as a professional astronomer behind and became a full-time writer, novelist and essayist, although the relationship of humans to space and cosmology, and the history of science, remained powerful themes in his later writing.

==Addendum==
There is an addendum to the catalogue called '''Uppsala General Catalogue Addendum''', which is abbreviated as '''UGCA'''.

==See also==
* [[List of astronomical catalogues]]
* [[Uppsala]]
* [[Uppsala Astronomical Observatory]]
* [[Royal Society of Sciences in Uppsala]]

==References==
{{Reflist}}

==External links==
* [https://heasarc.gsfc.nasa.gov/W3Browse/galaxy-catalog/ugc.html UGC - Uppsala General Catalog of Galaxies] {{Pd-notice}}
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[[Category:Astronomical catalogues of galaxies]]
[[Category:UGC objects|*]]
[[Category:UGCA objects| ]]
[[Category:1973 documents]]
[[Category:1973 in science]]