Legacy of Avicenna in Astronomy

The paper reassesses the largely neglected contribution of Avicenna (Ibn Sina, 980-1037) to medieval Tajik-Persian astronomy. Drawing on published primary and secondary sources, it reconstructs the main directions of his scientific activity - the construction of an observatory at Isfahan, the design of a high-precision angular instrument that anticipates the modern vernier principle, the formulation of an original method for determining terrestrial longitude from lunar culmination, a systematic refutation of predictive astrology, an optical explanation for the daytime invisibility of the fixed stars, and the earliest extant descriptions of both the transit of Venus on 24 May 1032 and the supernova SN 1006. These achievements not only anticipated comparable European advances by several centuries but also shaped subsequent developments within the Islamic and Latin astronomical traditions. The paper further notes Avicenna's modern scientific commemoration in the naming of asteroid (2755) Avicenna and the lunar crater Avicenna.