celestial equator (redirected from Equator (astronomy))

celestial equator: see equatorial coordinate system.

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celestial equator

the great circle lying on the celestial sphere the plane of which is perpendicular to the line joining the north and south celestial poles

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celestial equator [sə′les·chəl i′kwād·ər]

(astronomy)

The primary great circle of the celestial sphere in the equatorial system, everywhere 90° from the celestial poles; the intersection of the extended plane of the equator and the celestial sphere. Also known as equinoctial.