University of Tehran Press Journal for the History of Science 1735-0573 21 2 2024 01 21 An Observational History of Persia and the Islamic World until the “Mumtaḥan (Examined) Observations” (213 AH / 828 AD) An Observational History of Persia and the Islamic World until the “Mumtaḥan (Examined) Observations” (213 AH / 828 AD) 169 186 98376 10.22059/jihs.2024.356657.371782 FA Younes Karamati استادیار Journal Article 2024 02 16 Despite the emphasis of some astronomers of the Islamic period on the lack of observation between Ptolemy’s observations (ca. 130-141 AD) and “Mumtaḥan (Examinated) Observations”, scattered reports of observations at the same time, both in the Sassanid era and the Islamic period, can be seen in various sources. The present essay contains the analysis of the existing Information about these observations: three sets of Persian observations in the Sassanid era (ca. 470, 556, and ca. 633-634 AD), an anonymous observer’s observations in 90-100 AH / 709-718 AD in Bost (the present-day city Lashkargah in Afghanistan), the observations of Aḥmad Ibn Muḥammad al-Nahavandī al-Ḥāsib in Jundishapur in 170s AH /787-795 AD, and the observations probably made by Yaḥyā Ibn Abī Manṣūr in Merv in 202 AH / 817 AD or shortly before. All these observations took place in the geographical area of Iran. It seems that the researchers generally did not pay attention to the observations of Bost and Merv. Despite the emphasis of some astronomers of the Islamic period on the lack of observation between Ptolemy’s observations (ca. 130-141 AD) and “Mumtaḥan (Examinated) Observations”, scattered reports of observations at the same time, both in the Sassanid era and the Islamic period, can be seen in various sources. The present essay contains the analysis of the existing Information about these observations: three sets of Persian observations in the Sassanid era (ca. 470, 556, and ca. 633-634 AD), an anonymous observer’s observations in 90-100 AH / 709-718 AD in Bost (the present-day city Lashkargah in Afghanistan), the observations of Aḥmad Ibn Muḥammad al-Nahavandī al-Ḥāsib in Jundishapur in 170s AH /787-795 AD, and the observations probably made by Yaḥyā Ibn Abī Manṣūr in Merv in 202 AH / 817 AD or shortly before. All these observations took place in the geographical area of Iran. It seems that the researchers generally did not pay attention to the observations of Bost and Merv. https://jihs.ut.ac.ir/article_98376_c3e39a552d8c8528fd30992e46964381.pdf