Sinān al-Battānī, father of modern astronomy

Sinān al-Battānī, father of modern astronomy

By Ibrahim GIMBA, Abuja

Abū ʿAbdAllāh Muḥammad ibn Jābir ibn Sinān al-Raqqī al-Ḥarrānī aṣ-Ṣābiʾ al-Battānī was a Mesopotamian Arab astronomer and mathematician. He introduced several trigonometric relations, and his Kitāb az-Zīj was frequently quoted by many medieval astronomers, including Copernicus.

He was born in 858 AD, in Harran, Turkey and died in 929 AD, in Samarra, Iraq.

His parents are Jabir Ibn San’an al-Battani, and most notable in his work is Kitāb az-Zīj. He influenced the work of Abū al-Wafā’, al-Bīrūnī, and Copernicus

Al-Battani also known as you Albategnius was an Islamic astronomer and mathematician. He made important accurate measurements of the stars, moon and planets. His measurements and methods were used by later astronomers.

Biography
Al-Battani is sometimes known by a Latinised version of his name, variants being Albategnius, Albategni or Albatenius. His full name was Abu Abdallah Mohammad ibn Jabir ibn Sinan al-Raqqi al-Harrani al-Sabi al-Battani.

He was born in Harran, called Carrhae in earlier times by the Romans, which lies on the Balikh River, 38 km southeast of Urfa. His family had been members of the Sabian sect, a religious sect of star worshippers from Harran.

Although the identification is not certain, al-Battani’s father was probably Jabir ibn Sinan al-Harran who had a high reputation as an instrument maker in Harran. The name certainly makes the identification fairly certain and the fact that al-Battani himself was skilled in making astronomical instruments is a good indication that he learned these skills from his father.

Al-Battani made his remarkably accurate astronomical observations at Antioch and ar-Raqqah in Syria. The town of ar-Raqqah, where most of al-Battani’s observations were made, became prosperous when Harun al-Rashid, who became the fifth Caliph of the Abbasid dynasty on 14 September 786, built several palaces there. The town had been renamed al-Rashid at that time but, by the time al-Battani began observing there, it had reverted to the name of ar-Raqqah. The town was on the Euphrates River just west of where it joins the Balikh River (on which Harran stands).

Other information about al-Battani contained in the Fihrist is that he observed between the years 877 and 918 and that his star catalogue is based on the year 880. It also describes the end of his life which seems to have occurred during a journey he made to Baghdad to protest on behalf of a group of people from ar-Raqqah because they had been unfairly taxed. Al-Battani reached Baghdad and put his arguments but died on the return journey to ar-Raqqah. Al-Battani’s Kitab al-Zij is by far his most important work.

Main achievements of al-Battani’s Zij

He catalogued 489 stars. He refined the existing values for the length of the year, which he gave as 365 days 5 hours 46 minutes 24 seconds, and of the seasons. He calculated 54.5″ per year for the precession of the equinoxes and obtained the value of 23° 35′ for the inclination of the ecliptic.

Rather than using geometrical methods, as Ptolemy had done, al-Battani used trigonometrical methods which were an important advance. For example, he gives important trigonometric formulae for right-angled triangles such as
b sin (A) = a sin (90°−A)
b \sin(A) = a \sin(90° – A)
basin(A)=asin(90°−A).

Al-Battani showed that the farthest distance of the Sun from the Earth varies and, as a result, annular eclipses of the Sun are possible as well as total eclipses.