Az-Zarkali

(Abu Ishaq Ibrahim ibn Yahya Al-Naccache ibn-al-Zarkala Kurtubi)
(1028, Cordoba - 15.10.1100 (by dp. data 1087), ibid) --
A native of Cordoba, he worked in Toledo. Leading astronomer of his era. In Western Europe, was known as Arzachel (Arzahel; lats. spelling) and Arzaquiel (Spanish spelling). Participated in the creation of tables of Toledo. Among his works, in addition to treatises on the astrolabe (I), - "Introduction to the science of the stars" and "Processing canon Ammonium". Z. was the first astronomer to accurately determine the motion of the apogee of the Sun (aphelion of the Earth) relative to the stars - 12.04 "per year (according to sovr. Measurements - 11.8 "). He also invented the plane astrolabe.

B honor SW. named a mountain valley on the lunar surface - Arzachel (Arzachel).