First known ancient Greek map of night sky found hidden in Medieval palimpsest parchment revealed by multispectral imaging

Good news! What else can we discover in palimpsests?

Notice: There are very old Greek orthodox churches in Egypt! Saint Catherine's Monastery: "Built between 548 and 565, it is the oldest continuously inhabited Christian monastery in the world."

"A medieval parchment from a monastery in Egypt has yielded a surprising treasure. Hidden beneath Christian texts, scholars have discovered what seems to be part of the long-lost star catalogue of the astronomer Hipparchus — believed to be the earliest known attempt to map the entire sky. ..."

From the abstract:

"New evidence for ancient Greek astronomer Hipparchus’ lost Star Catalogue has come to light thanks to multispectral imaging of a palimpsest manuscript and subsequent decipherment and interpretation. This new evidence is the most authoritative to date and allows major progress in the reconstruction of Hipparchus’ Star Catalogue. In particular, it confirms that the Star Catalogue was originally composed in equatorial coordinates. It also confirms that Ptolemy’s Star Catalogue was not based solely on data from Hipparchus’ Catalogue. Finally, the available numerical evidence is consistent with an accuracy within 1° of the real stellar coordinates, which would make Hipparchus’ Catalogue significantly more accurate than his successor Claudius Ptolemy’s."

First known map of night sky found hidden in Medieval parchment Fabled star catalogue by ancient Greek astronomer Hipparchus had been feared lost.

New evidence for Hipparchus’ Star Catalogue revealed by multispectral imaging (open access)

Figure 3. Detail of f. 53v (yellow tracings based on full set of multispectral images).

The library of St Catherine’s Monastery on the Sinai Peninsula in Egypt yielded a palimpsest containing stellar coordinates by Hipparchus.