What do Al-Nayrizi and Avicenna have in common?
Al-Nayrizi: Abū’l-‘Abbās al-Faḍl ibn Ḥātim al-Nairīzī (Arabic: أبو العباس الفضل بن حاتم النيريزي‎ ‎ , Latin: "Anaritius, Nazirius" , 865–922) was a Persian mathematician and astronomer from Nayriz, Fars Province, Iran. Avicenna: Avicenna or Ibn Sīnā (Persian: ‎ ‎ ;  – June 1037) was a Persian polymath who is regarded as one of the most significant physicians, astronomers, thinkers and writers of the Islamic Golden Age.
astronomers