Abd al-Rahman as-Sufi

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Abd ar-Rahman as-Sufi (also under the names Abd al-Rahman al-Sufi and Abd ar-Rahman Abu l-Husain , Arabic عبد الرحمن بن عمر الصوفي, DMG ʿAbd ar-Raḥmān b. ʿUmar aṣ-Ṣūfī , known in the western world as Azophi , born December 7,  903 in Shahr-e Rey ; † May 25,  986 in Shiraz ) was a Persian astronomer .

Life and earnings

He lived in Isfahan at the court of the Emir Adud ad-Daula and studied the works of Greek astronomers, especially that of Claudius Ptolemy , whose “Great Astronomical System” was translated into Arabic around 800 (“ Almagest ”).

As-Sufi contributed to several corrections to the Ptolemaic list of stars, in particular through his own observations of the brightness and tried to be the first to relate the Greek and the traditional Arabic names of stars and constellations . He improved u. a. the calculation of the length of the solar year and dealt with the various uses of the astrolabe , an astronomical instrument already used by Ptolemy and handed down by the Arabs in the form of a disk with a sighting device, which serves the mechanical solution of astronomical and astronomical-geographical tasks.

He observed that the plane of the ecliptic is inclined in relation to the celestial equator and made a more accurate calculation of the tropical year .

The lunar crater Azophi (diameter 47 km) and the asteroid (12621) Alsufi bear his name.

Sagittarius constellation from the Book of Fixed Stars

Main work

As-Sufi published his main work, the book of fixed stars , around the year 964 in Arabic , the educational language of Islam. The book is a combination of Ptolemy's Almagest , Arabic tradition and his own observations. It contains illustrations of star constellations and descriptions of stars that include their position, brightness and color. The work was arranged according to constellations.

In it he mentions u. a. both the Large Magellanic Cloud , which he called al-Baqar al-abyad (the white ox), and the Andromeda Nebula , long before the former was sighted by European sailors at the beginning of the 16th century and the latter after the invention of the telescope by Simon in 1612 Marius was rediscovered.

Work editions

literature

  • Heinrich Suter : The mathematicians and astronomers of the Arabs and their works. Teubner, Leipzig 1900 ( digitized version , University and State Library of Saxony-Anhalt); Reprint: Apa-Oriental, Amsterdam 1981.

Web links

Commons : Abd al-Rahman al-Sufi  - Collection of images, videos and audio files