hour angle

Noun

WordNet 3.0

Noun (2)

the angular distance along the celestial equator from the observer's meridian to the hour circle of a given celestial bodySynonyms: 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 daySynonyms: hour angle HA

Webster's Dictionary (GCIDE)

Hour \Hour\, n. [OE. hour, our, hore, ure, OF. hore, ore, ure, F. heure, L. hora, fr. Gr. ?, orig., a definite space of time, fixed by natural laws; hence, a season, the time of the day, an hour. See Year, and cf. Horologe, Horoscope.]

1.The twenty-fourth part of a day; sixty minutes. [1913 Webster]

2.The time of the day, as expressed in hours and minutes, and indicated by a timepiece; as, what is the hour? At what hour shall we meet? [1913 Webster]

3.Fixed or appointed time; conjuncture; a particular time or occasion; as, the hour of greatest peril; the man for the hour. [1913 Webster]

Woman, . . . mine hour is not yet come.— John ii. 4.[1913 Webster]

This is your hour, and the power of darkness.— Luke xxii. 53.[1913 Webster]

4.pl. (R. C. Ch.) Certain prayers to be repeated at stated times of the day, as matins and vespers. [1913 Webster]

5.A measure of distance traveled. [1913 Webster]

Vilvoorden, three hours from Brussels.— J. P. Peters.[1913 Webster]

After hours, after the time appointed for one's regular labor.

Canonical hours. See under Canonical.

Hour angle (Astron.), the angle between the hour circle passing through a given body, and the meridian of a place.

Hour circle. (Astron.) (a) Any circle of the sphere passing through the two poles of the equator; esp., one of the circles drawn on an artificial globe through the poles, and dividing the equator into spaces of 15[deg], or one hour, each. (b) A circle upon an equatorial telescope lying parallel to the plane of the earth's equator, and graduated in hours and subdivisions of hours of right ascension. (c) A small brass circle attached to the north pole of an artificial globe, and divided into twenty-four parts or hours. It is used to mark differences of time in working problems on the globe.

Hour hand, the hand or index which shows the hour on a timepiece.

Hour line. (a) (Astron.) A line indicating the hour. (b) (Dialing) A line on which the shadow falls at a given hour; the intersection of an hour circle which the face of the dial.

Hour plate, the plate of a timepiece on which the hours are marked; the dial. --Locke.

Sidereal hour, the twenty-fourth part of a sidereal day.

Solar hour, the twenty-fourth part of a solar day.

The small hours, the early hours of the morning, as one o'clock, two o'clock, etc.

To keep good hours, to be regular in going to bed early. [1913 Webster]