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.

Also see

• Definition:Celestial Axis
• Definition:Celestial Pole

• Definition:Geographical Equator
• Definition:Galactic Equator

• Results about the celestial equator can be found here.

Sources

• 1976: W.M. Smart: Textbook on Spherical Astronomy (6th ed.) ... (previous) ... (next): Chapter $\text {II}$. The Celestial Sphere: $19$. Declination and hour angle.
• 1998: David Nelson: The Penguin Dictionary of Mathematics (2nd ed.) ... (previous) ... (next): celestial equator
• 1998: David Nelson: The Penguin Dictionary of Mathematics (2nd ed.) ... (previous) ... (next): celestial sphere $(1)$
• 2008: David Nelson: The Penguin Dictionary of Mathematics (4th ed.) ... (previous) ... (next): celestial equator
• 2008: David Nelson: The Penguin Dictionary of Mathematics (4th ed.) ... (previous) ... (next): celestial sphere $(1)$