S. Mohammad Mozaffari

Research Institute for Astronomy and Astrophysics of Maragha, Maragheh University, Iran


Ibn al-Zarqalluh’s discovery of the annual equation of the Moon

by S. Mohammad Mozaffari Published on: 9th February 2024

Ibn al-Zarqālluh (al-Andalus, d. 1100) introduced a new inequality in the longitudinal motion of the Moon into Ptolemy’s lunar model with the amplitude of 24′, which periodically changes in terms of a sine function with…

The Orbital Elements of Venus in Medieval Islamic Astronomy: Interaction Between Traditions and the Accuracy of Observations

by S. Mohammad Mozaffari Published on: 23rd November 2020

The orbital elements of each planet are the eccentricity and the direction of the apsidal line of its orbit defined by the ecliptic longitude of either of its apses, i.e., the two points on its…

The Observational Instruments at the Maragha Observatory after AD 1300

by S. Mohammad Mozaffari Published on: 5th November 2020

The present paper introduces, investigates, analyses, and comments on an anonymous treatise in Persian named al-Risāla al-Ghāzāniyya fi ’l-ālāt al-raṣadiyya, “Ghāzān’s (or Ghāzānid) treatise on the observational instruments”, which describes the structure, construction, and functions…

Biruni’s Telescopic-Shape Instrument for Observing the Lunar Crescent

by S. Mohammad Mozaffari Published on: 17th October 2020

This paper deals with an optical aid named barbakh that Abū al-Rayḥān al-Bīrūnī (973–1048 CE) proposes for facilitating the observation of the lunar crescent in his al-Qānūn al-Mas‘ūdī VIII.14. The device consists of a long…