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equatorial coordinate system

(latitude/longitude-like system for the celestial sphere)

The equatorial coordinate system is a spherical coordinate system used for directions in the celestial sphere, fixed to the stars/constellations as seen from Earth. Elements:

It (and the closely related International Celestial Reference System) is commonly used for planetary orbit calculation and its coordinates are those generally used in identifying and naming objects (e.g., J designators).

The Earth's precession results in a slow but never-ending shift in the equatorial coordinates that indicate a point on the celestial sphere: on the order of an arcsecond per month. This is a prime reason for specifying an epoch.

(coordinate system,equatorial,celestial sphere,Earth)

Referenced by:
celestial coordinate system
celestial sphere
galactic north
International Celestial Reference System (ICRS)
J designator