celestial equator

noun

, Astronomy, Navigation.

1. the great circle of the celestial sphere, lying in the same plane as the earth's equator.

celestial equator

noun

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

celestial equator

1. A great circle separating the northern and southern hemispheres of the celestial sphere and lying in the same plane as the Earth's equator. The celestial equator is a projection of the Earth's equator outward onto the celestial sphere and is used as the reference point in determining a celestial body's declination .

Word History and Origins

Origin of celestial equator¹

First recorded in 1870–75

Example Sentences

The second is the great watersnake, Hydra, which 4600 years ago stretched for 105° along the celestial equator of that day.

From Project Gutenberg

The Declination of a star is its angular distance north or south of the celestial equator.

From Project Gutenberg

The angle of elevation of the celestial equator to the horizon varies according to the position of the observer.

From Project Gutenberg

Then the zenith would be on the celestial equator and the north and south poles of the heavens would be on the horizon.

From Project Gutenberg

When the sun is south of the celestial equator its apparent daily path is the same as it would be for a star so situated.

From Project Gutenberg