Qāḍī Zāda al-Rūmī (1364 in Bursa, Ottoman Empire – 1436 in Samarqand, Timurid Empire), whose actual name was Salah al-Din Musa Pasha (qāḍī zāda means "son of the judge", al-rūmī "the Roman" indicating he came from Asia Minor, which was once Roman), was a Turkish astronomer and mathematician who worked at the observatory in Samarkand. He computed sin 1° to an accuracy of 10−12. Together with Ulugh Beg, al-Kāshī and a few other astronomers, Qāḍī Zāda produced the Zij-i-Sultani, the first comprehensive stellar catalogue since the Maragheh observatory's Zij-i Ilkhani two centuries earlier. The Zij-i Sultani contained the positions of 992 stars. Source: Wikipedia (en)