planisphere

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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.
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References in periodicals archive ?
On the rete appears a planispheric projection of the brightest stars in the northern sky; I have used the Yale Bright Star Catalogue (11) to mark all stars brighter than fourth magnitude.
As before, each represents an equal 30[degrees] portion of the ecliptic, though in the planispheric projection the northern constellations appear artificially shrunken compared to those in the south.
Chapter Titles (abbreviated): The Astrolabe, A Concise History, The Stereographic Projection, The Planispheric Astrolabe, Front, Drawing the Plate, The Rete, The Rule, The Back, Sample Problems, Southern Latitudes, Calculation, Universal Astrolabes, The Saphea Arzachelis, Orthographic Astrolabes, De la Hire's Astrolabe, Quadrants, The Astrolabe Quadrant, The Prophatius Quadrant, Sutton's Quadrant, Horizontal Instruments, Astrolabe Variations, Astrolabe Clocks, Astronomical Background, Calculations, Computers and Astrolabes, Design Layout and Fabrication, Appendices, Glossary, Bibliography, Index.