Colure, in astronomy, is either of the two principal meridians of the celestial sphere.[1] The term is now rarely used and may be considered obsolete.

Orange = equinoctial colure
Blue = solstitial colure
G = equinoctial colure
H = solstitial colure

Equinoctial colure

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The equinoctial colure is the meridian or great circle of the celestial sphere which passes through the celestial poles and the two equinoxes:[1] 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:

Solstitial colure

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The solstitial colure is the meridian or great circle of the celestial sphere which passes through the poles and the two solstices:[1] 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:

See also

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References

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  •   This article incorporates text from a publication now in the public domainChisholm, Hugh, ed. (1911). "Colure". Encyclopædia Britannica. Vol. 6 (11th ed.). Cambridge University Press. p. 748.
  • Harley, John Brian; Woodward, David (1987). Cartography in the Traditional Islamic and South Asian Societies. The History of cartography. Vol. 2. University of Chicago Press. p. 28. ISBN 978-0-226-31635-2. OCLC 13456456. OL 9455351M.
  • Geminus; Evans, James; Berggren, J. L. (2006). Geminos's Introduction to the phenomena: a translation and study of a Hellenistic survey of astronomy. Princeton University Press. p. 130. ISBN 978-0-691-12339-4. OCLC 70232402. OL 15978783M.
  • Ovason, David (1999). The Secret Architecture of our Nation's Capital. HarperCollins. p. 98. ISBN 978-006095368-3. OCLC 50409366.
  • Kaler, Jim. "Pi Aurigae." Pi Aurigae. N.p. 22 Feb. 2008. Web.