celestial pole, one of the two points at which the earth's axis of rotation intersects the celestial sphere. The celestial pole is important as a reference point in the equatorial coordinate system; the celestial meridian passes through it, as do the hour circles of the stars. The polestar (see Polaris) lies within 0.5° of the north celestial pole. Although there is no bright star near the south celestial pole, the Southern Cross (see Crux) points directly to it. The altitude of the celestial pole in an observer's hemisphere is equal to the observer's latitude on the earth.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.