The meaning of the Sky of Salamanca

TL;DR

This paper examines the Sky of Salamanca, analyzing whether its depiction is based on astrological or astronomical principles, and concludes it aligns with 15th-century astronomical knowledge rather than astrology.

Contribution

It provides a detailed analysis showing the Sky of Salamanca reflects 15th-century astronomical understanding, challenging previous astrological interpretations.

Findings

The planetary configuration does not match Ptolemaic astrological systems.

The depiction aligns with the astronomical knowledge from the Almagest.

The painted configuration dates to August 1475.

Abstract

After presenting the main characteristics of the Sky of Salamanca, we analyse whether what is represented in it is motivated by astrological or astronomical considerations. We will see that the astrological explanation based on the system of planetary houses described in Claudius Ptolemy's Tetrabiblos does not correspond to the planetary configuration we see in the salmantine vault. Finally, we will conclude that the astronomical interpretation of the Sky of Salamanca is justified by the representation of the Universe known in the 15th century according to the Almagest, by the placement of the stars in the constellations according to that work and by the dating of the painted planetary configuration, which circumstantial evidence places in August 1475.