hour circle

noun
a great circle on the celestial sphere that passes through both celestial poles
Hypernyms: ↑great circle

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noun
1. : a circle of the celestial sphere passing through the two poles
2. : the circle upon an equatorial telescope mounted perpendicular to the polar axis and graduated in hours and subdivisions of hours of right ascension
3. : a small metal circle attached to the pole of an artificial globe and divided into 24 parts to mark differences of time at different places

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Astron.
a great circle on the celestial sphere passing through the celestial poles and containing a point on the celestial sphere, as a star or the vernal equinox. Also called circle of declination.
[1665-75]

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hour circle,
Astronomy. any great circle on the celestial sphere which passes through its poles, equivalent in the celestial system of coordination to a meridian of the earth, and, like it, used in measuring longitude.

Useful english dictionary. 2012.

Look at other dictionaries:

  • Hour circle — 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 …   The Collaborative International Dictionary of English

  • hour-circle — hourˈ circle noun (astronomy) 1. A great circle passing through the celestial poles 2. The equivalent of a meridian 3. The circle of an equatorial which shows the right ascension • • • Main Entry: ↑hour …   Useful english dictionary

  • hour circle — n. Astron. any great circle of the celestial sphere which passes through the celestial poles and is therefore perpendicular to the celestial equator …   English World dictionary

  • hour circle — Astron. a great circle on the celestial sphere passing through the celestial poles and containing a point on the celestial sphere, as a star or the vernal equinox. Also called circle of declination. [1665 75] * * * ▪ astronomy       in astronomy …   Universalium

  • hour circle — hour′ cir cle n. astron. a great circle on the celestial sphere passing through the celestial poles and containing a point on the celestial sphere, as a star or the vernal equinox • Etymology: 1665–75 …   From formal English to slang

  • hour circle — Any great circle joining the celestial poles and passing through a point on the celestial sphere. All celestial bodies are positioned on particular hour circles. Unlike celestial meridians, which remain fixed with respect to the earth, hour… …   Aviation dictionary

  • hour circle — noun Date: 1690 a circle on the celestial sphere that passes through both celestial poles …   New Collegiate Dictionary

  • hour circle — (Astronomy) great circle that passes through both poles of the celestial sphere …   English contemporary dictionary

  • hour-circle — n. Meridian, great circle of the sphere …   New dictionary of synonyms

  • hour circle — /ˈaʊə sɜkəl/ (say owuh serkuhl) noun any great circle in the celestial sphere passing through the celestial poles …   Australian English dictionary

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