Al-Battani (d. 929)
Al-Battani wrote The Sabian Tables (al-Zij al-Sabi), a very influential work for centuries after him. Al-Battani's work also includes timing of the new moons, calculation of the length of the solar and sideral year, the prediction of eclipses and the phenomenon of parallax. Al-Battani also popularised if not discovered the first notions of trigonometrical ratios used today, and made serious emendations to Ptolemy.
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by: FSTC Limited, Mon 16 July, 2007