Ibn Yunus

(redirected from Abu'l-Hasan ibn Yunus)
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Ibn Yunus

 

Born 950; died 1009. Arab astronomer.

Ibn Yunus conducted extensive astronomical observations at an observatory near Cairo and compiled astronomical tables of the motion of the sun, moon, and planets, which for about two centuries were the best tables of their kind. He also compiled trigonometric tables. Ibn Yunus refined the values of the precessional constant and the angle of inclination of the ecliptic to the equator. He perfected the methods of the solution of plane and spherical triangles (the method of auxiliary angles).

REFERENCE

Berry, A. Kratkaia istoriia astronomii, 2nd ed. Moscow-Leningrad, 1946. (Translated from English.)
The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
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