Colure, inastronomy, is either of the two principalmeridians of thecelestial sphere.[1] The term is now rarely used and may be considered obsolete.
Theequinoctial colure is themeridian orgreat circle of the celestial sphere which passes through thecelestial poles and the twoequinoxes:[1] thefirst point of Aries and thefirst point of Libra. It is the great circle consisting of all points on the celestial sphere withRight Ascension equal to 0 hours or 12 hours (equivalent to RA 0° / 180°).
The equinoctial colure passes through the following constellations:
Thesolstitial colure is the meridian or great circle of the celestial sphere which passes through the poles and the twosolstices:[1] thefirst point of Cancer and thefirst point of Capricorn. It is the great circle consisting of all points on the celestial sphere withRight Ascension equal to 6 hours or 18 hours (equivalent to RA 90° / 270°).
The solstitial colure passes through the following constellations:
This article incorporates text from a publication now in thepublic domain: Chisholm, Hugh, ed. (1911). "Colure".Encyclopædia Britannica. Vol. 6 (11th ed.). Cambridge University Press. p. 748.
