ESHS/HSS Annual Meeting

Tycho Brahe and the Iberian Cosmographers

• In Event: Heavens, Earth, and Water in the Early Modern Iberian World

English Abstract

The Danish nobleman Tycho Brahe (1546-1601) was one of the most influential astronomers of the seventeenth century, becoming an authority in observational matters. Still during his remarkable activity on the Island of Hven, Tycho studied in detail the work De Crepusculis (1542) by the Portuguese cosmographer and mathematician Pedro Nunes (1502-1578). It was in this book, which Tycho quotes in several passages of his works, that he found an ingenious solution to improve the accuracy of angular measurements, having tested it in four instruments. It was only after Tycho Brahe's unexpected death that his books were more widely disseminated, making their way into the commercial circuits. Only then, but with a remarkable haste, Tycho's new astronomical data and parameters were appropriated by Iberian cosmographers such as Andrés García de Céspedes (c.1545-1611), Simão de Oliveira (fl.1600), Manuel de Figueiredo (1568-c.1622), or Valentim de Sá (fl.1620). Evidence of cosmographer’s interest in Tycho’s books can also be found in ownerships marks of surviving copies – a recently discovered Astronomiae instauratae mechanica (1602) holds an autograph of Manuel de Meneses (c.1565-1628), appointed Chief Cosmographer of Portugal in 1624. As a result solar declinations, as well as star positions, became accessible to scholars and navigators with a higher degree of accuracy, as soon as Tycho’s data became more widely available, showing that Cosmography was by no means a crystalized field.

Author

• Luís Tirapicos, CIUHCT, University of Lisbon