Read this: Al-Azhar University, founded in Cairo, Egypt in 975 by the Ismaʻīlī Shīʻī Fatimid dynasty as a jāmiʻah, had individual faculties for a theological seminary, Islamic law and jurisprudence, Arabic grammar, Islamic astronomy, early Islamic philosophy and logic in Islamic philosophy. The postgraduate doctorate in law was only obtained after "an oral examination to determine the originality of the candidate's theses", and to test the student's "ability to defend them against all objections, in disputations set up for the purpose." ‘Abd al-Laṭīf al-Baghdādī also delivered lectures on Islamic medicine at al-Azhar, while Maimonides delivered lectures on medicine and astronomy there during the time of Saladin. Another early jāmiʻah was the Niẓāmīyah of Baghdād (founded 1091), which has been called the "largest university of the Medieval world." Mustansiriya University, established by the ʻAbbāsid caliph al-Mustanṣir in 1233, in addition to teaching the religious subjects, offered courses dealing with philosophy, mathematics and the natural sciences.
Now answer this question, if there is an answer (If it cannot be answered, return "unanswerable"): Who was an astronomy professor at Al-Azhar University?
Maimonides