Contents

'Abd al-Rahman al-Sufi was one of the famous nine Muslim astronomers. His name implies that he was from a Sufi Muslim background. He lived at the court of Emir Adud ad-Daula in Isfahan, Persia, and worked on translating and expanding Greek astronomical works, especially the Almagest of Ptolemy. He contributed several corrections to Ptolemy's star list and did his own brightness and magnitude estimates which frequently deviated from those in Ptolemy's work.

He was a major translator into Arabic of the Hellenistic astronomy that had been centered in Alexandria, Egypt, the first to attempt to relate the Greek with the traditional Arabic star names and constellations, which were completely unrelated and overlapped in complicated ways.

He observed that the ecliptic plane is inclined with respect to the celestial equator and more accurately calculated the length of the tropical year. He observed and described the stars, their positions, their magnitudes and their colour, setting out his results constellation by constellation. For each constellation, he provided two drawings, one from the outside of a celestial globe, and the other from the inside (as seen from the earth).

Since 2006, Astronomy Society of Iran – Amateur Committee (ASIAC) hold an international Sufi Observing Competition in the memory of Sufi. The first competition was held in 2006 in the north of Semnan Province[9] and the second was held in the summer of 2008 in Ladiz near the Zahedan. More than 100 attendees from Iran and Iraq participated in the event.[10]

^Al-Qifti. Ikhbar al-'ulama' bi-akhbar al-hukama ("History of Learned Men"). In: Άbdul-Ramān al-Şūfī and his Book of the Fixed Stars: A Journey of Re-discovery by Ihsan Hafez, Richard F. Stephenson, Wayne Orchiston (2011). In: Orchiston, Wayne, Highlighting the history of astronomy in the Asia-Pacific region: proceedings of the ICOA-6 conference. Astrophysics and Space Science Proceedings. New York: Springer. ISBN978-1-4419-8161-5. "... is the honored, the perfect, the most intelligent and the friend of the King Adud al-Dawla Fanakhasru Shahenshah Ibn Buwaih. He is the author of the most honored books in the science of astronomy. He was originally from Nisa and is of a Persian descent."

^Robert Harry van Gent. Biography of al-Sūfī. "The Persian astronomer Abū al-Husayn ‘Abd al-Rahmān ibn ‘Umar al-Sūfī was born in Rayy (near Tehrān) on 7 December 903 [14 Muharram 291 H] and died in Baghdād on 25 May 986 [13 Muharram 376 H] ... the Persian astronomer Abū al-Husayn ‘Abd al-Rahmān ibn ‘Umar al-Sūfī who was commonly known by European astronomers as Azophi Arabus". University of Utrecht, Netherlands. Retrieved 2014-1-11

^Selin, Helaine (2008). Encyclopaedia of the history of science, technology, and medicine in non-western cultures. Berlin New York: Springer. p. 160. ISBN9781402049606. Al-Sūf ī was an astronomer in the Arabic–Islamic area. He was of Persian origin, but wrote in Arabic, the language of all science in that time.

^Robert Harry van Gent. Biography of al-Sūfī. "The Persian astronomer Abū al-Husayn ‘Abd al-Rahmān ibn ‘Umar al-Sūfī was born in Rayy (near Tehrān) on 7 December 903 [14 Muharram 291 H] and died in Baghdād on 25 May 986 [13 Muharram 376 H] ... the Persian astronomer Abū al-Husayn ‘Abd al-Rahmān ibn ‘Umar al-Sūfī who was commonly known by European astronomers as Azophi Arabus". University of Utrecht, Netherlands. Retrieved 2014-1-11