Category:Definitions/Hour Angle

This category contains definitions related to Hour Angle.
Related results can be found in Category:Hour Angle.

Let $P$ be a point on the celestial sphere.

The hour angle of $P$ is the angular distance measured westwards along the celestial equator from the vernal equinox.

That is, it is the angular distance measured westwards along the celestial equator between the observer's meridian and the hour circle of $P$.