Zij-i Ilkhani

Zij-i Ilkhani was a highly influential medieval Persian astronomical handbook created by the astronomer Nasir al-Din al-Tusi in the 13th century. It combined existing ancient and Islamic astronomical knowledge into a comprehensive work that improved the understanding of planetary motions and celestial calculations. The Zij served as a practical tool for astronomers and navigators, featuring detailed tables, charts, and mathematical formulas. Its innovations, such as refining planetary models, significantly advanced medieval astronomy and influenced later scholars in both the Islamic world and Europe.