View source for Colure

{{Short description|Principal meridians of the celestial sphere}}
{{distinguish|Coulure}}
[[File:Colure.png|thumb|upright=1.3|'''Orange''' = equinoctial colure<br> '''Blue''' = solstitial colure]]
[[File:EB1711 Armillary Sphere.png|thumb|'''G''' = equinoctial colure<br> '''H''' = solstitial colure]]
'''Colure''', in [[astronomy]], is either of the two principal [[meridian (astronomy)|meridian]]s of the [[celestial sphere]].{{sfn|Chisholm|1911}} The term is now rarely used and may be considered obsolete.

==Equinoctial colure==
The ''equinoctial colure'' is the [[meridian (astronomy)|meridian]] or [[great circle]] of the celestial sphere which passes through the [[celestial pole]]s and the two [[equinox]]es:{{sfn|Chisholm|1911}} the [[first point of Aries]] and the [[first point of Libra]]. It is the great circle consisting of all points on the celestial sphere with [[Right Ascension]] equal to 0 hours or 12 hours (equivalent to RA 0° / 180°).

The equinoctial colure passes through the following constellations:
{{columns-list|colwidth=125px|
*[[Ursa Minor]]
*[[Camelopardalis]]
*[[Draco (constellation)|Draco]]
*[[Ursa Major]]
*[[Coma Berenices]]
*[[Virgo (constellation)|Virgo]]
*[[Corvus (constellation)|Corvus]]
*[[Hydra (constellation)|Hydra]]
*[[Centaurus]]
*[[Crux]]
*[[Musca]]
*[[Chamaeleon]]
*[[Octans]]
*[[Tucana]]
*[[Phoenix (constellation)|Phoenix]]
*[[Sculptor (constellation)|Sculptor]]
*[[Cetus]]
*[[Pisces (constellation)|Pisces]]
*[[Pegasus (constellation)|Pegasus]]
*[[Andromeda (constellation)|Andromeda]]
*[[Cassiopeia (constellation)|Cassiopeia]]
*[[Cepheus (constellation)|Cepheus]]
}}

==Solstitial colure==
The ''solstitial colure'' is the meridian or great circle of the celestial sphere which passes through the poles and the two [[solstice]]s:{{sfn|Chisholm|1911}} the [[first point of Cancer]] and the [[first point of Capricorn]]. It is the great circle consisting of all points on the celestial sphere with [[Right Ascension]] equal to 6 hours or 18 hours (equivalent to RA 90° / 270°).

The solstitial colure passes through the following constellations:
{{columns-list|colwidth=125px|
*[[Ursa Minor]]
*[[Cepheus (constellation)|Cepheus]]
*[[Camelopardalis]]
*[[Auriga (constellation)|Auriga]]
*[[Taurus (constellation)|Taurus]]
*[[Orion (constellation)|Orion]]
*[[Monoceros (constellation)|Monoceros]]
*[[Lepus (constellation)|Lepus]]
*[[Columba (constellation)|Columba]]
*[[Pictor]]
*[[Dorado]]
*[[Mensa (constellation)|Mensa]]
*[[Octans]]
*[[Apus]]
*[[Pavo (constellation)|Pavo]]
*[[Ara (constellation)|Ara]]
*[[Corona Australis]]
*[[Sagittarius (constellation)|Sagittarius]]
*[[Serpens]]
*[[Ophiuchus]]
*[[Hercules (constellation)|Hercules]]
*[[Draco (constellation)|Draco]]
}}

==See also==
* [[Celestial coordinate system]]
* [[Ecliptic]]
* [[Celestial sphere]]
* [[Right ascension]]
* [[Equinox]]
* [[Solstice]]

==References==
{{reflist}}
* {{EB1911|wstitle=Colure|volume=6|page=748}}
* {{cite book | first1 = John Brian | last1 = Harley | first2 = David | last2 = Woodward | title = Cartography in the Traditional Islamic and South Asian Societies | series = The History of cartography | volume = 2 | publisher = [[University of Chicago Press]] | date = 1987 | issue = 1 | isbn = 978-0-226-31635-2 | page = 28 | oclc = 13456456 | ol = 9455351M }}
* {{cite book | author = Geminus | author-link = Geminus | first2 = James | last2 = Evans | first3 = J. L. | last3 = Berggren | title = Geminos's Introduction to the phenomena: a translation and study of a Hellenistic survey of astronomy | publisher = [[Princeton University Press]] | date = 2006 | isbn = 978-0-691-12339-4 | page = 130 |oclc = 70232402 | ol = 15978783M }}
* {{cite book | last = Ovason | first = David | title = The Secret Architecture of our Nation's Capital | publisher = [[HarperCollins]] | date = 1999 | page = [https://archive.org/details/secretarchitectu00ovas/page/98 98] | isbn = 978-006095368-3 | oclc = 50409366 | url-access = registration | url = https://archive.org/details/secretarchitectu00ovas/page/98 }}
* Kaler, Jim. "Pi Aurigae." ''[http://stars.astro.illinois.edu/sow/piaur.html Pi Aurigae]''. N.p.&nbsp;22 Feb. 2008. Web.

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[[Category:Astronomical coordinate systems]]
[[Category:Solstices]]

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