Ibn al-A^ҁlam:^ҁAlī ibn al-Ḥusayn Abū al-Qāsim al-^ҁAlawī al-Sharīf al-Ḥusaynī

Died possibly Baghdad, (Iraq), 985

Ibn al-A^ҁlam composed a zīj (astronomical handbook with tables) that later influenced astronomy in Iraq and Iran, especially Naṣīr al-Dīn al- Ṭūsī ’s īlkhānī Zīj (thirteenth century), and in Byzantium. He was also reported to have practiced astrology under the patronage of the Būyid ruler of Baghdad^ҁAḍud al-Dawla (978–983) and to have cultivated musical theory. Very little is known about Ibn al-A^ҁlam’s life and work. His zīj, unfortunately lost, is only known by later references in other astronomical works. One of the names given to this work, al-Zīj al-^ҁAḍudī, derives from the name of his patron. It was also known as al-Zīj al-Sharīf, from the name of the author, and al-Zīj al-Baghdādī, which either refers to his place of residence or may indicate that the original tables were based on the prime meridian of Baghdad.

Ibn al-A^ҁlam’s work attracted significant interest, mainly because of the observations attributed to him; the values from his zījare...