The first map of the sky dates back over 2,200 years
The oldest known map of the sky dates back to 2,200 years and is attributed to Hipparchus of Nicaea
In October 2022 was reported the news of the discovery an ancient star catalog attributed to the Greek astronomer Hipparchus of Nicaea, who lived in the 2nd century BC.
The manuscript 'Codex Climaci Rescriptus' contains a series of Syriac translations of the texts of the Christian monk John Climacus dating back to the 10th or 11th century AD.
The scribe did not use a new parchment to write the translation, but recycle an old one that was erased in the 9th or 10th century, and which was none other than the one that Hipparchus of Nicaea had used more than a millennium earlier to write down his celestial map.
The practice of reusing writing parchment was common in the past.
Story of the discovery
In 2012 Peter Williams from the University of Cambridge asked his students as part of a summer project to read John Climacus' Christian Code folios. One of his students, Jamie Klair, first identified references to the star catalog in a Greek fragment that was often attributed to the astronomer Eratosthenes, who lived shortly before Hipparchus of Nicaea.
In 2017, ghostly images of nine sheets of the codex demonstrated the presence of hidden text. This included myths about the origin of the stars by Eratosthenes and parts of a poem by the Greek writer Aratus entitled “Phenomena.”
However, it was only in 2021 that Williams observed the presence of astronomical measurements, so he contacted Victor Gysembergh of the French National Center for Scientific Research to evaluate his discovery. “It was immediately clear that we had stellar coordinates,” said Gysembergh, who together with his colleague at the Sorbonne University in Paris, Emmanuel Zingg, deciphered the detected passage, a long page in which he describes both the length and width in degrees of the constellation Corona Borealis, located in the northern celestial hemisphere.
Scientists verified with computational tools that the coordinates of the stars have a precession of one degree, which coincides with the observations made in the year 129 BC, i.e. the period in which Hipparchus worked.
The data was used to corroborate the coordinates of three other constellations (Ursa Major, Ursa Minor and Draco) which are shown in another manuscript, called 'Aratus Latinus' and whose authorship is also attributed to Hipparchus.
It seems that Greek mathematician Claudius Ptolemy's star catalog was not based solely on Hipparchus' data. Previously, Ptolemy was believed to have stolen them and claimed them as his own.
“Available numerical evidence is consistent with an accuracy of one degree of actual stellar coordinates, which would make Hipparchus' catalog significantly more accurate than that of his successor Claudius Ptolemy,” the scientist said, concluding that as techniques improved imaging, more stellar coordinates can be found for analysis.
