THÉORIE DES COMÈTES ET OBSERVATIONS INÉDITES EN OCCIDENT MUSULMAN

Abstract

In this paper, we present the Aristotelian theory of comets, which is well known in the Muslim West through the commentaries of Ibn Rušd and Ibn Bāǧǧa. This aspect is covered three centuries later in an unknown manuscript attributed to the famous mathematician Ibn Ġāzī al-Miknāsī (1437-1513), and this text is not present in the known list of his works. The author devotes a part of his manuscript to the comet astrology following Ptolemy, and introduces a critical position of Iḫwān al-Ṣafā’, characterized by the rejection of the sidereal comets idea. We are also interested in comet classifications given by Ibn Ġāzī and another author ‘Alī al-Antākī. We found that the content of the De cometis of pseudo-Ptolemy is analogous with the text of Ibn Ġāzī, and almost identical to the text of al-Antākī. Then, we are interested in observations of comets from the 9th to the end of the 19th century in North Africa and in Islamic Spain (Andalusia), recorded in some Arabic manuscripts on astronomy and history, which have never been the subject of an extensive study. The studied observations are: the two comets X/975 P1 and X/998 D1 reported by an anonymous author of the 15th century, the X/1381 V1 comet reported by Ibn al-Qāḍī (1553-1616), the passage of Halley's comet in 1456 reported by Muḥammad al-Zarkašī (1434-1525), the C/1743 X1 comet observed by ‘Abd al-Razzāq ibn Ḥamadūš (1695-1785), which confirm its fan structure, the two observations of Ibn ‘Alī al-Šrīf al-Šalāṭī of the D/1770 L1, and especially the C/1769 P1 comet. The graphic representation of this latter comet is unprecedented in the Muslim West.