Al-Battānī (other names include Albategnius, Albategni and Albatenius; born about 858 – died 929) was an Arab astronomer, astrologer and mathematician. He is considered an important astronomer and mathematician of the Islamic Golden Age. His discoveries about trigonometry were often quoted by medieval European astronomers; including by Copernicus. He was from Harran. His full name was Abū ʿAbd Allāh Muḥammad ibn Jābir ibn Sinān al-Raqqī al-Ḥarrānī al-Ṣābiʾ al-Battānī.