|Biographical detail : ||An outstanding astronomer of the Middle Ages.
Al-Sufi was the first astronomer to describe the ‘nebulosity’ of the nebula in Andromeda in his book of constellation (atlas of heavens). He named the southern group of stars al-Baqar al-Abyad or the ‘White Bull’ after receiving reports from Arabs navigators in the Malay Archipelago. We now know this group of stars as Nubecula Major (the greater Magellanic Cloud).
Al-Sufi prepared charts of the heavens from his own observations and carefully adjudged their magnitudes. His book ‘Kitab al-Kawatib al-Thabit al-Musawwar’ was a masterpiece on stellar astronomy. The book is considered important even now, available in the original Arabic and in French translation by Schjellerup, for the study of proper motions and long period variables – included in it theta Eridani among the 13 brightest stars then known. Ulugh Beg, the grandson of Tamelane, in 1437, found it to be the first magnitude in his list fixed stars.
One of the greatest astronomers who wrote the Book Of The Fixed Stars. This book and the works of the Ibn Yunus and Ulugh Beg constituted the three masterpieces of Muslim observational astronomy.
Al-Sufi stated that the colour of the Sirms (alpha canes majoris) does not change, which was confirmed by later observations. He also observed the colour of Algol, beta Persei, (Arabic al-Ghoul), to be ruddy.
Beer and Madler in their famous work Der Mond (1837) mention a surface feature of the moon after As-Sufi (Azophi). It is a mountainous ring twenty-six miles in diameter in the ninth section of the lunar map.
Al-Sufi, known in the west as Azophi, was born as Abdul Rahman al-Sufi.