Biography:Muhyi al-Dīn al-Maghribī

Short description: Medieval Spanish astronomer

Ibn Abī al‐Shukr
Died	June 1283 CE Maragheh
Academic work
Era	Islamic Golden Age
School or tradition	Maliki
Main interests	Astronomy, Astrology and Mathematics
Notable ideas	New astronomical parameters

Muḥyī al‐Milla wa al‐Dīn Yaḥyā Abū ʿAbdallāh ibn Muḥammad ibn Abī al‐Shukr al‐Maghribī al‐Andalusī (Arabic: محيي الدين المغربي; died 1283 CE) was an Andalusī astronomer, astrologer and mathematician of the Islamic Golden Age. He belonged to the group of astronomers associated with the Maragheh observatory, most notably Nasir al-Din al-Tusi. In astronomy, Ibn Abi al-Shukr carried out a large‐scale project of systematic planetary observations, which led to the development of several new astronomical parameters.

He died in Maragheh in modern-day Iran in June 1283 CE.

Time in the Maragheh Observatory

Before joining in the Maghrib observatory, which was founded by the Mongol Ilkhanid dynasty in Iran, Muhyi al-Dīn al-Maghribī had worked for King Nasir of Damascus. This relationship was ultimately cut short when in 1257, the king was killed by the Mongols in the Siege of Aleppo conflict. It was after this that Muhyi al-Dīn al-Maghribī was sent to Maragheh to work alongside Nasir al-Din al-Tusi in the acclaimed observatory, and continued to work on his numerous observations until his death in 1283. During his time at the observatory, the amount of observations conducted by al-Maghribī was extensive, observing up to a total of eight of the brightest stars, of which he used the latitudes collected to compare with the values within ancient computations. He concluded that the difference between his latitudes and ancients were not substantial, and any inconsistences were in fact due to the observations and not the subject itself. In Muhyi al-Dīn al-Maghribī's Talkhīṣ al‐Majisṭī, he commentates on Ptolemy's Almagest, presenting his own observations and hypothesizes in addition with it. For instance, al-Maghribī supposed that the precession would only occur in a motion that was uniform and continuous at a rate that was 1° for ever 66 years from his systematic stellar observations.

Works

Astronomy

Marāgha observatory where Ibn Abi al-Shukr carried out his planetary observations

His known works on astronomy include:

• Tasṭīḥ al‐asṭurlāb: a description of the construction and use of the astrolabe.
• Maqāla fī istikhrāj taʿdīl al‐nahār wa saʿat al‐mashriq wa‐ʾl‐dāʾir min al‐falak bi‐ṭarīq al‐handasa: a description of the geometrical methods used to determine the meridian line, the rising amplitude, and the revolution of the sphere.
• Risālat al‐Khaṭā wa‐ʾl‐īghūr: a chronological work on the Chinese and Uighur calendars, which was later translated from Arabic and Persian into Chinese.
• Three zijes:
  • Tāj al‐azyāj wa‐ghunyat al‐muḥtāj (The crown of astronomical handbooks), also known as Al‐muṣaḥḥaḥ bi‐adwār al‐anwār maʿa al‐raṣad wa‐ʾl‐iʿtibār.
  • Adwār al‐anwār madā al‐duhūr wa‐ʾl‐akwār: contains results of the astronomical observations he carried out in Marāgha.
  • ʿUmdat al‐ḥāsib wa‐ghunyat al‐ṭālib
• Three commentaries on Ptolemy's Almagest:
  • Talkhīṣ al‐Majisṭī (Compendium of the Almagest): based on his observations carried out between 1264 and 1275 CE.
  • Khulāṣat al‐Majisṭī (Summary of the Almagest)
  • Muqaddimāt tataʿallaq bi‐ḥarakāt al‐kawākib (Prolegomena on the motion of the stars): contains five geometric premises on the planetary motions in the Almagest.

Astrology

Ibn Abī al‐Shukr's astrological works were mainly devoted to horoscopes and planetary conjunctions used to tell the future.

Mathematics

Muhyi al-Din is most known for his works in trigonometry, Book on the theorem of Menelaus, Treatise on the calculation of sines. He is also known for his commentaries on classic Greek mathematical works, in particular, his commentary on Book XV of Elements about measurements of the regular polyhedra. His writings on trigonometry "contain certain original elements".