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The two celestial poles are the points on the celestial sphere through which the Earth's rotation axis passes, i.e., the points that are at the zenith for someone precisely at Earth's north or south pole. The two celestial poles are termed the north celestial pole and the south celestial pole. In the equatorial coordinate system, they correspond to the two points with declinations of 90° and -90° (the right ascension is moot). The position of the celestial poles shift with the Earth's precession of the equinoxes, roughly 20 arcseconds per year.