Timocharis

Timocharis of Alexandria (c. 320 BC; † 260 BC) was a Greek astronomer and philosopher, born probably in Alexandria. He was a contemporary of Euclid. The lunar crater Timocharis was named after him.

Around 300 BC, he created the first star catalog. Over 150 years later, Hipparchus compared his own star catalog with the Timo Charis and discovered that the longitude of the stars had changed over time, which led him to determine the first value of the precession of the equinoxes.

As the first known astronomer, he made a record of the observation of Mercury. Also, are by him in connection with the Kallippischen cycle four -logged before astronomical events that he precisely dated, both in the Attic and in the ancient Egyptian calendar.