colure

1 9.9

A circle in the sky that passes through the north and south celestial poles and an equinox or solstice

noun
/kəˈlʊr/

Specialized

: colure

Astronomers use the colure to help define important points on the celestial sphere.

Examples

The solstitial colure passes through the celestial poles and the solstices.
Ancient star maps often marked the position of each colure for reference.
The colure is important.
Look at the colure!
The equinoctial colure is essential for understanding the position of celestial bodies at the equinoxes.
Astronomers often use the colure to map the cyclical paths of stars across the sky.
During the solstice, the sun casts its longest shadows along the colure that intersects the celestial poles.

Surface Forms

colure singular

colures plural

Etymology

Colure is easiest to remember if you imagine a 'column' running through the sky: it names an imaginary great circle that passes through the celestial poles and through the equinoxes or solstices. So, a colure is like a sky 'column' that helps astronomers mark important points on the celestial sphere.