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Hipparchus was an ancient Greek astronomer of Nicaea, c190BC-c120BC. Among his work was a star catalog that classified stars by brightness, into six magnitude classes, the system which has evolved into the present magnitude system. The catalog is lost, though a fragment was discovered in 2022 in the form of erased text evident on a medieval manuscript. Note that an ancient statue, Farnese Atlas, which depicts the constellations on a globe, has occasionally been theorized to reflect the catalog. Hipparchus also made measurements of the seasons, the lunar cycle, and the solar year.
The astrometry satellite name, Hipparcos, was clearly inspired by the ancient astronomer.