A folio from the Codex Climaci Rescriptus. Credit: © Peter Malik
Key Points:
- Multispectral imaging has revealed new evidence for ancient Greek astronomer Hipparchus’ lost Star Catalog.
- The results confirm that the Star Catalog was originally composed in equatorial coordinates.
- The findings are the most authoritative to date and allows major progress in the reconstruction of Hipparchus’ Star Catalog.
Using multispectral imaging technologies, researchers have found fragments of the Star Catalog composed by the Greek astronomer Hipparchus during the 2nd century BC. These texts had been erased from a manuscript during the medieval period in order to reuse the pages.
In fact, the text was only known through the writings of Claudius Ptolemy, another ancient astronomer who composed his own catalog nearly 400 years after Hipparchus. But now, scientists from the French National Centre for Scientific Research (CNSR) have deciphered the descriptions of four constellations from Hipparchus' Star Catalog.
Written between 170 and 120 BC, Hipparchus' Star Catalog it is the oldest known attempt to determine the precise position of fixed stars by associating them with numerical coordinates.
The fragments of the Star Catalog are the oldest known to date and bring major advances in its reconstruction. Firstly, they refute a widespread idea that Claudius Ptolemy's Star Catalogue is merely a "copy" of Hipparchus' as the observations of the four constellations are different. Furthermore, Hipparchus' data are verified to the nearest degree, which would make his catalog much more accurate than Ptolemy's, even though it was composed several centuries earlier.
For the research team this major discovery sheds new light on the history of astronomy in antiquity and on the beginnings of the history of science. Above all, it illustrates the power of advanced techniques, such as multispectral imaging, whose application on illegible palimpsests could save numerous lost texts on philosophy, medicine or horticulture.
Information provided by CNRS.