Qutb al-DīnShīrāzī's Planetary Theory in IkhtyārātMuzaffarī

The main problem of Ptolemaic model of the superior planets was related to the“equant point”. It is a geometrical point with respect to which the motion of the deferent sphere is uniform. But it cannot be acceptable on the basis of Aristotle's philosophy on the motions of celestial spheres. Astronomers of Maragha School devised some new models to avoid this problem, while they were in accordance with Ptolemy's observations. Qutb al-DīnShīrāzī(d. 1311) has provided his own model for superior planets in his works: Nihāyat al-idrākfīdirāyat al-aflāk andal-Tuhfa al-Shāhīyya in Arabic, and Ikhtiārāt-i Muzaffarī in Persian. His model in Ikhtiārāt has not been studied yet and it is different from the one introduced bySaliba (1979) and Kennedy (1966). Here, I introduce Qutb al-Dīn's model for superior planets provided in eighth chapter of the second book of Ikhtiārāt-i Muzaffarī.I also discuss a conflict between observations and the theory which this model involves.