Al Battani (c. 850- c. 923) was an Arab astronomer and mathematician (also spelled Al Batani, Latinized Albategnius, Albategni, Albatenius; Arabic أبو عبد الله محمد بن جابر بن سنان الحراني الصابي البتاني ; full name Abū ʿAbdullāh Muḥammad ibn Jābir ibn Sinān ar-Raqqī al-Ḥarrani aṣ-Ṣabiʾ al-Battānī), born in Harran near Urfa. His epithet as-Sabi suggests that among his ancestry were members of the Sabian sect who worshiped the stars, however, his full name affirms that he was Muslim. His best-known achievement was the determination of the solar year as being 365 days, 5 hours, 46 minutes and 24 seconds. Centuries: 8th century - 9th century - 10th century Decades: 800s - 810s - 820s - 830s - 840s - 850s - 860s - 870s - 880s - 890s - 900s 850 851 852 853 854 855 856 857 858 859 Events Samara the Sweet is born. ... Events June 15 - Battle of Soissons: King Robert I of France is killed, King Charles the Simple is arrested by the supporters of Duke Rudolph of Burgundy. ... The Arabs (Arabic: عرب Ê»arab) are a large and heterogeneous ethnic group found throughout the Middle East and North Africa, originating in the Arabian Peninsula of southwest Asia. ... Lunar astronomy: the large crater is Daedalus, photographed by the crew of Apollo 11 as they circled the Moon in 1969. ... Arabic (; , less formally, ) is the largest member of the Semitic branch of the Afro-Asiatic language family (classification: South Central Semitic) and is closely related to Hebrew and Aramaic. ... Ruins of the Ulu Cami (Great Mosque) at Harran Harran, also known as Carrhae, is an archeological site in present day southeastern Turkey, 24 miles (39 kilometers) southeast of Sanli Urfa. ... Sanli Urfa (in Turkish Şanlıurfa) is a city in eastern Turkey, and the provincial capital of Sanliurfa Province. ... Sabian is a term that has been more or less inaccurately used to describe at least three religious groups (see Mandaeanism, Harranians or Sabeans, and Sabaeans). ... A Muslim (Arabic: مسلم) (sometimes also spelled Moslem) is an adherent of Islam. ...

He produced a number of trigonometrical relationships:

He also solved the equation sin x = a cos x discovering the formula:

and used al-Marwazi's idea of Tangents ("shadows") to develop equations for calculating tangents and cotangents, compiling tables of them. Ahmad ibn Abdallah Habash al-Hasib al-Marwazi was a Persian astronomer and mathematician from Merv in Khorasan, Persia. ...

Al Battani worked in Syria, at ar-Raqqah and at Damascus, where he died. He was able to correct some of Ptolemy's results and compiled new tables of the Sun and Moon, long accepted as authoritative, discovered the movement of the Sun's apogee, treats the division of the celestial sphere, and introduces, probably independently of the 5th century indian astronomer Aryabhata, the use of sines in calculation, and partially that of tangents, forming the basis of modern trigonometry. He also calculated the values for the precession of the equinoxes (54.5" per year) and the inclination of Earth's axis (23° 35'). Cooling down the bread, in the background the Museum of ar-Raqqah Ar-Raqqah (الرقة, also spelled Rakka), is a city in north central Syria located on the north bank of the Euphrates River, about 160 km east of Aleppo. ... Damascus by night, pictured from Jabal Qasioun; the green spots are minarets Damascus (Arabic officially دمشق Dimashq, colloquially ash-Sham الشام) is the capital city of Syria. ... Claudius Ptolemaeus, given contemporary German styling, in a 16th century engraved book frontispiece. ... The Sun is the star at the center of our Solar system. ... Crust composition Oxygen 43% Silicon 21% Aluminium 10% Calcium 9% Iron 9% Magnesium 5% Titanium 2% Nickel 0. ... This article is about several astronomical terms (apogee & perigee, aphelion & perihelion, generic equivalents based on apsis, and related but rarer terms. ... // Overview Events Romulus Augustus, Last Western Roman Emperor 410: Rome sacked by Visigoths 452: Pope Leo I allegedly meets personally with Attila the Hun and convinces him not to sack Rome 439: Vandals conquer Carthage At some point after 440, the Anglo-Saxons settle in Britain. ... Aryabhata (आर्यभट) Ä€ryabhaá¹­a) (476 - 550) is the first of the great astronomers of the classical age of India. ... In mathematics, the trigonometric functions are functions of an angle, important when studying triangles and modeling periodic phenomena. ... In mathematics, the word tangent has two distinct, but etymologically related meanings: one in geometry, and one in trigonometry. ... Trigonometry (from the Greek trigonon = three angles and metro = measure) is a branch of mathematics dealing with angles, triangles and trigonometric functions such as sine, cosine and tangent. ... Precession refers to a change in the direction of the axis of a rotating object. ...

His most important work is the Kitāb az-Zīj ('the book of tables') with 57 chapters, which by way of Latin translation as De Motu Stellarum by Plato Tiburtinus (Plato of Tivoli) in 1116 (printed 1537 by Melanchthon, annotated by Regiomontanus), had great influence on European astronomy. A reprint appeared at Bologna in 1645. Plato's original manuscript is preserved at the Vatican; and the Escorial Library possesses in manuscript a treatise by Al Battani on astronomical chronology. Apparently, he translated information on the Astrolabe into Arabic for the first time. ... Events Baldwin I of Jerusalem undertakes an invasion of Egypt The modern book of separate pages stitched together is invented in China Construction starts on the Chennkesava temple The Aztecs leave Aztlán searching for the site of what will eventually become Tenochtitlán and later Mexico City Births Deaths... Events January 6 - Alessandro de Medici assassinated August 25 - The Honourable Artillery Company, the oldest surviving regiment in the British Army, and the second most senior, was formed. ... Philipp Melanchthon (February 16, 1497 - April 19, 1560) was a German theologian and writer of the Protestant Reformation and an associate of Martin Luther. ... Johannes Müller von Königsberg (June 6, 1436 – July 6, 1476), known by his Latin pseudonym Regiomontanus, was an important German mathematician, astronomer and astrologer. ... World map showing Europe A satellite composite image of Europe Europe is conventionally considered one of the seven continents which, in this case, is more a cultural and political distinction than a physiogeographic one. ... Bologna (from Latin Bononia, BulÃ¥ggna in the local dialect) is the capital city of Emilia-Romagna in northern Italy, between the Po River and the Apennines. ... // Events January 10 - Archbishop Laud executed on Tower Hill, London. ... The facade of the chapel, in the baroque style of Jesuit churches, is integrated with the palatial facade El Escorial is an immense palace, monastery, museum, and library complex located at San Lorenzo de El Escorial (also San Lorenzo del Escorial), a town 45 kilometres northwest of Madrid in the...

Honors

• The Albategnius crater on the Moon was named after him.

• In the fictional Star Trek universe, the Excelsior-class starship USS Al-Batani NCC-42995, mentioned on Star Trek: Voyager as Kathryn Janeway's first deep space assignment, was named for him.

Albategnius is an ancient lunar impact crater located in the central highlands. ... Crust composition Oxygen 43% Silicon 21% Aluminium 10% Calcium 9% Iron 9% Magnesium 5% Titanium 2% Nickel 0. ... The starship Voyager (NCC-74656), an Intrepid-class starship. ...

External links

• John J. O'Connor and Edmund F. Robertson. Al Battani at the MacTutor archive.