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 ?
The front of the mother of the astrolabe is shown in Figure 2; the planispheric starchart in Figure 3 rotates over the top of the middle portion of Figure 2.
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.
About half the book deals with planispheric astrolabes.
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.
a version known as the planispheric astrolabe was in use.
The second half of the book concentrates on Hale-Bopp and contains interviews with the discoverers, details of observations made so far, planispheric charts, and general hints about observing prospects.