Noun
(astronomy) the angular distance of a celestial point measured westward along the celestial equator from the zenith crossing; the right ascension for an observer at a particular location and time of day
the angular distance along the celestial equator from the observer's meridian to the hour circle of a given celestial body
Source: WordNetAt solar noon the hour angle is 0.000 degrees, with the time before solar noon expressed as negative degrees, and the local time after solar noon expressed as positive degrees. Source: Internet
Explanatory Supplement (1992), p. 724. Relation with the right ascension The local hour angle (LHA) of an object in the observer's sky is : (If result is negative, add 360 degrees. Source: Internet
Glossary, s.v. hour angle, hour circle, sidereal time. Source: Internet
Replace with declination and longitude difference with hour angle, and change the sign (since the hour angle is positive westward instead of east). Source: Internet
The hour angle of a point is the angle between two planes: one containing the Earth's axis and the zenith (the meridian plane), and the other containing the Earth's axis and the given point (the hour circle passing through the point). Source: Internet
Unlike right ascension, hour angle is always increasing with the rotation of the Earth. Source: Internet