Abū al-ʿAbbās Aḥmad ibn Muḥammad ibn Kathīr al-Farghānī. (800/805-870) also known as Alfraganus in the West, was an Arab or Persian Sunni Muslim astronomer, and one of the most famous astronomers in the 9th century. The crater Alfraganus on the Moon is named after him.
Statue of al-Farghani Rhoda Island, Cairo. Al-Farghani supervised the building of the Nilometer in Cairo. builder
He was involved in the calculation of the diameter of the Earth by the measurement of the meridian arc length, together with a team of scientists under the patronage of al-Ma'mūn in Baghdad. Later he moved to Cairo, where he composed a treatise on the astrolabe around 856. There he also supervised the construction of the large Nilometer on the island of al-Rawda (in Old Cairo) in the year 861.
His textbook Kitāb fī Jawāmiʿ ʿIlm al-Nujūm (كتاب في جوامع علم النجومA Compendium of the Science of the Stars) or Elements of astronomy on the celestial motions, written about 833, was a competent descriptive summary of Ptolemy's Almagest, while using the findings and revised values of earlier Islamic astronomers. It was translated into Latin in the 12th century and remained very popular in Europe until the time of Regiomontanus. Dante Alighieri's knowledge of Ptolemaic astronomy, which is evident in his Divina Commedia as well as other works such as the Convivio, seems to have been drawn from his reading of Alfraganus. In the 17th century the Dutch orientalist Jacob Golius published the Arabic text on the basis of a manuscript he had acquired in the Near East, with a new Latin translation and extensive notes.
Jacobus Golius (ed.), كتاب محمد بن كثير الفرغاني في الحركات السماوية وجوامع علم النجوم، بتفسير الشيخ الفاضل يعقوب غوليوس / Muhammedis Fil. Ketiri Ferganensis, qui vulgo Alfraganus dicitur, Elementa astronomica, Arabicè & Latinè. Cum notis ad res exoticas sive Orientales, quae in iis occurrunt, Amsterdam 1669; Reprint Frankfurt 1986 and 1997.
El-Fergânî, The Elements of Astronomy, textual analysis, translation into Turkish, critical edition & facsimile by Yavuz Unat, edited by Şinasi Tekin & Gönül Alpay Tekin, Harvard University 1998.
Richard Lorch (ed.), Al-Farghānī on the Astrolabe. Arabic text edited with translation and commentary, Stuttgart, 2005, ISBN 3-515-08713-3.
Yavuz Unat, El-Fergânî, Cevami İlm en-Nucûm ve Usûl el-Harekât es-Semâviyye, Astronominin Özeti ve Göğün Hareketlerinin Esası, T.C. Kültür ve Turizm Bakanlığı, Bilimin ve Felsefenin Doğulu Öncüleri Dizisi 14, Ankara 2012.
Yavuz Unat, “Fergânî’nin ‘Astronominin Özeti ve Göğün Hareketlerinin Esasları’ Adlı Astronomi Eseri”, DTCF Dergisi, Cilt 38, Sayı 1-2, Ankara 1998, s. 405–423.