hour angle

hour angle

n. Abbr. ha

The angular distance, measured westward along the celestial equator, between the celestial meridian of the observer and the hour circle passing through a celestial body.

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hour angle

n

(Astronomy) the angular distance along the celestial equator from the meridian of the observer to the hour circle of a particular celestial body

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hour angle

The angular distance, measured westward along the celestial equator, between the celestial meridian of the observer and the hour circle passing through a celestial body. A body's hour angle is measured in hours, minutes, and seconds, and corresponds to its right ascension as measured with respect to the observer's meridian (which changes with time) rather than the vernal equinox (which is fixed on the celestial equator). A celestial object that crossed the observer's meridian 3 hours and 20 minutes ago has an hour angle of +3 hours 20 minutes. An object that will not cross the meridian for another 3 hours and 20 minutes has an hour angle of -3 hours 20 minutes.

Thesaurus

Noun	1.	hour angle - the angular distance along the celestial equator from the observer's meridian to the hour circle of a given celestial body distance - the property created by the space between two objects or points
	2.	hour angle - (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 HA astronomy, uranology - the branch of physics that studies celestial bodies and the universe as a whole angular distance - the angular separation between two objects as perceived by an observer; "he recorded angular distances between the stars"