Description: In equatorial coordinate systems, declination is one of two coordinates used to specify an object's position in the sky. Specifically, declination is the angular distance of the object to the celestial equator, commonly measured in degrees: positive for objects in the northern hemisphere, with a minus sign for objects in the southern hemisphere. In this way, declination is analogous to geographic latitude on Earth's surface. The celestial equator roughly corresponds to the projection of Earth's equator onto the celestial sphere, but modern coordinate systems like the International Celestial Reference System (ICRS) instead define the celestial equator without reference to the Earth, using the positions of very distant celestial objects in the sky for reference.

Related Terms:

• Celestial Coordinates
• Celestial Equator
• Equator
• Latitude
• Right Ascension (RA)

Term and definition status: This term and its definition have been approved by a research astronomer and a teacher

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