noun
- two great circles on the celestial sphere that pass through the celestial poles and intersect at right angles, one passing through the equinoxes and the other through the solstices
Usage: astronomy
Examples
- The colures divide the celestial sphere into four equal parts.
- Astronomers use the colures as reference lines for celestial navigation.
- The equinoctial colure passes through the vernal and autumnal equinox points.
- The solstitial colure intersects the celestial sphere at the summer and winter solstice points.
- Ancient astronomers relied on the colures to map star positions.
- The two colures meet at the north and south celestial poles.