Celestial Equator

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Celestial Equator

Each day and night as the fixed stars appear to rotate around the earth like a giant celestial sphere, the circumpolar stars (above the horizon in the north) turn in circles around the north celestial pole (Polaris, the north star). Perpendicular to the north celestial pole is the celestial equator, which lies directly above any observer located on the equator of the Earth.

In their daily or diurnal motion, stars located on the celestial equator rise due east and set due west as seen from anywhere on Earth. Example: Mintaka, the top star of Orion's belt.

You can trace the course of the celestial equator even if there are no stars visible (see below). However, in late autumn it runs eastward from the setting Summer Triangle through Pisces, Cetus, Orion, Monoceros, and Hydra. In late spring....


Observe in the planetarium and/or with a model celestial sphere:

Equatorial Coordinates


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