{{Short description|Principal meridians of the celestial sphere}} {{distinguish|Coulure}} thumb|upright=1.3|'''Orange''' = equinoctial colure<br> '''Blue''' = solstitial colure thumb|'''G''' = equinoctial colure<br> '''H''' = solstitial colure '''Colure''', in astronomy, is either of the two principal meridians 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 or great circle of the celestial sphere which passes through the celestial poles and the two equinoxes:{{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 *Ursa Major *Coma Berenices *Virgo *Corvus *Hydra *Centaurus *Crux *Musca *Chamaeleon *Octans *Tucana *Phoenix *Sculptor *Cetus *Pisces *Pegasus *Andromeda *Cassiopeia *Cepheus }}
==Solstitial colure== The ''solstitial colure'' is the meridian or great circle of the celestial sphere which passes through the poles and the two solstices:{{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 *Camelopardalis *Auriga *Taurus *Orion *Monoceros *Lepus *Columba *Pictor *Dorado *Mensa *Octans *Apus *Pavo *Ara *Corona Australis *Sagittarius *Serpens *Ophiuchus *Hercules *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. 22 Feb. 2008. Web.
{{Portal bar|Astronomy|Stars|Spaceflight|Outer space|Solar System}}
Category:Astronomical coordinate systems Category:Solstices
{{astronomy-stub}}