Abū al‐ʿUqūl Muḥammad ibn Aḥmad al‐Ṭabarī (flourished in

Yemen Yemen (; ar, ٱلْيَمَن, al-Yaman), officially the Republic of Yemen,, ) is a country in Western Asia. It is situated on the southern end of the Arabian Peninsula, and borders Saudi Arabia to the Saudi Arabia–Yemen border, north and ...

during the 14th century) was a leading

astronomer An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical objects such as stars, planets, moons, comets and galaxies – in either ...

Ta'izz Taiz ( ar, تَعِزّ, Taʿizz) is a city in southwestern Yemen. It is located in the Yemeni Highlands, near the port city of Mocha on the Red Sea, at an elevation of about above sea level. It is the capital of Taiz Governorate. With a populat ...

and the first teacher of astronomy at the Muʾayyadiyya Madrasa. Of

Iranian Iranian may refer to: * Iran, a sovereign state * Iranian peoples, the speakers of the Iranian languages. The term Iranic peoples is also used for this term to distinguish the pan ethnic term from Iranian, used for the people of Iran * Iranian lan ...

origin, he is known for compiling the largest single corpus of tables for astronomical timekeeping in a specific latitude during medieval times, with over 100,000 entries. Another interesting feature of his work was determining the latitude of Ta'izz as 13° 37' (where the actual is 13° 35').

Life

His epithet al-Tabarī suggests that he or his family stemmed from

Tabaristan Tabaristan or Tabarestan ( fa, طبرستان, Ṭabarestān, or mzn, تبرستون, Tabarestun, ultimately from Middle Persian: , ''Tapur(i)stān''), was the name applied to a mountainous region located on the Caspian coast of northern Iran. ...

, a region in northern

Iran Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkmeni ...

. He lived in Yemen during the time of the

Rasulid The Rasulids ( ar, بنو رسول, Banū Rasūl) were a Sunni Muslim dynasty who ruled Yemen from 1229 to 1454. History Origin of the Rasulids The Rasulids took their name from al-Amin's nickname "Rasul". The Zaidi Shi'i Imams of Yemen we ...

Sultan

al-Ashraf Umar II Al‐Malik Al‐Ashraf (Mumahhid Al‐Din) Umar Ibn Yūsuf Ibn Umar Ibn Alī Ibn Rasul (), also as Umar Ibn Yusuf (or also Al-Asharaf Umar II) was the third Rasulid sultan and also an mathematician, astronomer and physician. Biography Umar Ibn ...

and was contemporary to another famous astronomer Muḥammad ibn Abī Bakr al‐Fārisī.

Works

* ''Al‐Zīj al‐mukhtār min al‐azyāj'' a compilation of different books of

zij A zij ( fa, زيج, zīj) is an Islamic astronomical book that tabulates parameters used for astronomical calculations of the positions of the Sun, Moon, stars, and planets. Etymology The name ''zij'' is derived from the Middle Persian term ' ...

that is based heavily on the ''Ḥākimī Zīj'' of

Ibn Yunus Abu al-Hasan 'Ali ibn 'Abd al-Rahman ibn Ahmad ibn Yunus al-Sadafi al-Misri (Arabic: ابن يونس; c. 950 – 1009) was an important Egyptian astronomer and mathematician, whose works are noted for being ahead of their time, having been based ...

. Some of his original additions were astronomical tables specific to Yemen. * ''Mirʾāt al‐zamān'' (lit. "Mirror of the Time"), a large corpus of tables for astronomical timekeeping computed for Ta'izz at latitude 13° 37' and

obliquity In astronomy, axial tilt, also known as obliquity, is the angle between an object's rotational axis and its orbital axis, which is the line perpendicular to its orbital plane; equivalently, it is the angle between its equatorial plane and orbi ...

23° 35', including tables of the

hour angle In astronomy and celestial navigation, the hour angle is the angle between two planes: one containing Earth's axis and the zenith (the '' meridian plane''), and the other containing Earth's axis and a given point of interest (the ''hour circle ...

and the time since sunrise. It also contains tables of the solar altitude and longitude and the altitude of various other fixed stars. His altitude tables are similar to those used in Iraq or Iran, rather than ones found in Egypt. His tables are extant in copies found in Mocha in 1795. * An

almanac An almanac (also spelled ''almanack'' and ''almanach'') is an annual publication listing a set of current information about one or multiple subjects. It includes information like weather forecasts, farmers' planting dates, tide tables, and othe ...

linking agricultural features to astronomical events.

Notes

References

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{{DEFAULTSORT:Abu Al-Uqul 14th-century Iranian astronomers Yemenite people of Iranian descent Astronomers of the medieval Islamic world