Cleostratus

Cleostratus
This article concerns the Greek astronomer. For the article on the lunar crater named for him, see Cleostratus (crater).

Cleostratus (ca. 520 BC; possibly 548 BC to 432 BC) was an astronomer of ancient Greece. He was a native of Tenedos, and the Chaldean astronomer Naburimannu may have been a contemporary of him. He is believed by some scholars to have introduced the zodiac (beginning with Aries and Sagittarius) and the solar calendar to Greece from Babylonia. Censorinus (De Die Natali, c. 18) considers Cleostratus to have been the real inventor of the octaeteris, or cycle of eight years. The octaeteris was used before the Metonic cycle of 19 years, and was popularly attributed to Eudoxus. Theophrastus (de Sign. Pluv., p. 239, ed. Basil. 1541) mentions him as a meteorological observer along with Matricetas of Methymna and Phaeinus of Athens. Gaius Julius Hyginus (Poetica Astronomica, ii. 13) says that Cleostratus first pointed out the two stars in Auriga called Haedi. The crater Cleostratus on the Moon is named after him.

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