Discovery of extracts from a lost astronomical catalogue

A folio from the Codex Climaci Rescriptus © Peter Malik - They prove that Hipparchus' data were significantly more accurate than those of another catalogue composed centuries later. Researchers from the CNRS, Sorbonne Université and Tyndale House (affiliated with the University of Cambridge) have recently found fragments of the Star Catalogue composed by the Greek astronomer Hipparchus during the 2nd century BC. These texts, which had been erased from a manuscript during the medieval period in order to reuse the pages, were uncovered using multispectral imaging technologies. The study of these extracts, published in the Journal for the History of Astronomy on October 18, 2022, sheds new light on astronomy in antiquity. Old grimoires, even for the most Cartesian minds, often contain coveted secrets, such as the fragments of an ancient astronomical treatise lost for centuries: the Hipparchus Star Catalogue. Written between 170 and 120 BC by the Greek astronomer Hipparchus, it is the oldest known attempt to determine the precise position of fixed stars by associating them with numerical coordinates. Until now, this text was known only through the writings of Claudius Ptolemy, another ancient astronomer who composed his own catalogue nearly 400 years after Hipparchus.