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There are different celestial coordinate systems each using a coordinate grid projected on the celestial sphere, in analogy to the geographic coordinate system used on the surface of the Earth. The coordinate systems differ only in their choice of the fundamental plane, which divides the sky into two equal hemispheres along a great circle. (The fundamental plane of the geographic system is the Earth's equator). Each coordinate system is named for its choice of fundamental plane; below the name of a pole and the names of the coordinates are also shown:

• Horizontal coordinate system - horizon - zenith/ nadir - altitude - azimuth
• Equatorial coordinate systemThe equatorial coordinate system is probably the most widely used celestial coordinate system, whose equatorial coordinates are: declination right ascension or hour angle It is the most closely related to the geographic coordinate system, because they use - celestial equatorThe celestial equator is a great circle on the imaginary celestial sphere, which could be constructed by inflating the Earth's equator until it intersects with said sphere. The celestial equator is inclined by ~23. 5°, with respect to the ecliptic plane; - celestial poleThe two celestial poles are the imaginary points where the Earth's spin axis intersects the celestial sphere. The sky appears to drift overhead from east to west, completing a full circuit around the sky in 24 ( sidereal) hours. This phenomenon is due to - declinationIn astronomy declination (dec is one of the two coordinates of the equatorial coordinate system, the other being either right ascension or hour angle. Dec is comparable to latitude, projected unto the celestial sphere, and is measured in degrees north of - right ascensionRight ascension (RA; symbol α: Greek letter alpha) is the astronomical term for one of the two coordinates of a point on the celestial sphere when using the equatorial coordinate system. The other coordinate is the declination. RA is comparable to l or hour angleIn astronomy, an object's hour angle (HA) is defined as the difference between the current local sidereal time (LST) and the right ascension (RA) of the object: :HA LST RA Thus, the object's hour angle indicates how much sidereal time has passed since the
• Ecliptic coordinate systemThe ecliptic coordinate system is a celestial coordinate system that uses the ecliptic for its fundamental plane. The ecliptic is the path that the sun appears to follow across the sky over the course of a year. It is also the projection of the Earth's or - eclipticThe ecliptic is the geometric plane that contains the orbit of the Earth. The orbits of most planets in the Solar System lie very close to it. Seen from the Earth, this is a bisecting great circle, superimposed upon the celestial sphere, which contains th - ecliptic pole - ecliptic latitude - ecliptic longitude
• Galactic coordinate system
• Supergalactic coordinate system