Timocharis

Timocharis of Alexandria (Greek: Τιμόχαρις; c. 320 – 260 BC) was a Greek astronomer and philosopher. Likely born in Alexandria, he was a contemporary of Euclid.

What little is known about Timocharis comes from citations by Ptolemy in the Almagest. These indicate that Timocharis worked in Alexandria during the 290s and 280s BCE. Ptolemy lists the declination of 18 stars as recorded by Timocharis or Aristillus in roughly the year 290 BCE. Between 295 and 272 BCE, Timocharis recorded four lunar occultations and the passage of the planet Venus across a star. These were recorded using both the Egyptian and Athenian calendars. The observed stellar passage by Venus may have occurred on October 12, 272 BCE when the planet came within 15 arcminutes of the star η Virginis.