Definition:Celestial Equator

Definition
Consider the celestial sphere with observer $O$.

Let $P$ be the north celestial pole.

The great circle whose plane is perpendicular to $OP$ is known as the celestial equator.


 * Celestial-Sphere.png

Also see

 * Definition:Celestial Axis
 * Definition:Celestial Pole


 * Definition:Geographical Equator
 * Definition:Galactic Equator