celestial pole

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.

celestial pole Either of the two points about which the celestial sphere appears to rotate each day. The celestial poles lie on the celestial sphere directly above the Earth's geographical poles, and are 90° from the celestial equator. Because of precession, the celestial poles describe a circle around the ecliptic poles every 25 800 years.

celestial axis The line joining the north and south celestial poles, about which the celestial sphere rotates.