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planisphere
pla·ni·sphere P0350700 (plā′nĭ-sfîr′)n.1. A representation of a sphere or part of a sphere on a plane surface.2. Astronomy A polar projection of half or more of the celestial sphere on a chart equipped with an adjustable overlay to show the stars visible at a particular time and place.
pla′ni·spher′ic (-sfîr′ĭk, -sfĕr′-), pla′ni·spher′i·cal (-ĭ-kəl) adj.planisphere (ˈplænɪˌsfɪə) n (Physical Geography) a projection or representation of all or part of a sphere on a plane surface, such as a polar projection of the celestial sphere onto a chart[C14: from Medieval Latin plānisphaerium, from Latin plānus flat + Greek sphaira globe] planispheric adjplan•i•sphere (ˈplæn əˌsfɪər, ˈpleɪ nə-)
n. 1. a map of half or more of the celestial sphere with a device for indicating the part of a given location visible at a given time. 2. a projection or representation of the whole or a part of a sphere on a plane. [1350–1400; Middle English planisperie < Medieval Latin plānisphaerium; see plani-, sphere] plan`i•spher′i•cal (-ˈsfɛr ɪ kəl) plan`i•spher′ic, plan`i•spher′al, adj. planispherea map showing half or more of the sphere of the heavens, indicating which part is visible at what hour from a given location. — planispheric, planispherical, adj.See also: Astronomy
a map showing half or more of the sphere of the heavens, indicating which part is visible at what hour from a given location. — planispheric, planispherical, adj.See also: Maps
an astrolabe.See also: RepresentationTranslations
planisphere
planisphere (plan -ă-sfeer) A two-dimensional map projection centered on the northern or southern pole of the celestial sphere that shows the principal stars of the constellations, the Milky Way, etc., and is equipped with a movable overlay to indicate the stars visible at a particular time on any day of the year for a particular zone of terrestrial latitude.Planisphere the representation of a sphere on a plane in a normal (polar) stereographic projection. The planisphere was used until the 17th century to determine the times of the rising and setting of celestial bodies. It was usually a coordinate grid etched on a metal disk about whose center an alidade that facilitated calculations rotated. The planisphere fell into disuse with the introduction of special tables and nomographs. planisphere[′plan·ə‚sfir] (mapping) A representation, on a plane, of the celestial sphere, especially one on a polar projection, with means provided for making certain measurements such as altitude and azimuth. |