Hipparchus star catalog

[3] The catalog was lost to history, until parts of it were rediscovered in 2022 in the Codex Climaci Rescriptus, an ancient palimpsest found in Saint Catherine's Monastery on Mount Sinai.

[4] During a multispectral image survey of the ancient Greek palimpsest known as the Codex Climaci Rescriptus in 2012, Jamie Klair, then an undergraduate student at Cambridge University, noticed that some of the folios' undertext had an astronomical nature.

Researchers believe that other palimpsests in Saint Catherine's Monastery of the Mount Sinai, where the Codex Climaci Rescriptus was found, may contain more fragments of the star catalog.

Folios 47–54 and 64 of the palimpsest were originally part of an old codex that contained Aratus' Phaenomena and related writings, which were dated to the fifth or sixth century CE based on palaeographic evidence.

The "Hipparcos Catalogue", which contains 118,218 stars with the maximum level of precision documented, was created using calculations from observations by the primary instrument.