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abstraction > mathematical concept > geometrical object > plane > equator

equator
subject			fact

equator	has definition The great circle on the surface of a body formed by the intersection of the surface with the plane passing through the center of the body perpendicular to the axis of rotation. (See celestial equator.)
	is a kind of plane
plane	has dimensions 2

Kinds of equator :

• celestial equator (2 facts) - Projection of the Earth's equator as a line across the sky (so that to an observer actually on the equator, such a line would pass through the zenith). The directional bearing of a star is given in terms of its right ascension round the celestial equator.
• galactic equator (2 facts) - The primary circle defined by the central plane of the Galaxy.