A forgotten solar model

  title={A forgotten solar model},
  author={S. Mozaffari},
  journal={Archive for History of Exact Sciences},
  • S. Mozaffari
  • Published 2016
  • Mathematics
  • Archive for History of Exact Sciences
This paper analyses a kinematic model for the solar motion by Quṭb al-Dīn al-Shīrāzī, a thirteenth-century Iranian astronomer at the Marāgha observatory in northwestern Iran. The purpose of this model is to account for the continuous decrease of the obliquity of the ecliptic and the solar eccentricity since the time of Ptolemy. Shīrāzī puts forward different versions of the model in his three major cosmographical works. In the final version, in his Tuḥfa, the mean ecliptic is defined by an… Expand
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