- This article concerns the Greek astronomer. For the article on the lunar crater named for him, see Cleostratus (crater).
Cleostratus (b. ca. 520 BC; d. possibly 548 BC to 432 BC) was an astronomer of ancient Greece. He was a native of Tenedos. He is believed by some scholars to have introduced the zodiac (beginning with Aries and Sagittarius) and the solar calendar to Greece from Babylonia.
Pliny the Elder writes in his Natural History: "Anaximander the Milesian, in the 58th olympiad, is said to have been the first who understood its obliquity, and thus opened the road to a correct knowledge of the subject. Afterwards Cleostratus made the signs in it, first marking those of Aries and Sagittarius; Atlas had formed the sphere long before this time."
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.
- ^ E. J. Webb, Cleostratus Redivivus, The Journal of Hellenic Studies, Vol. 41, Part 1 (1921), pp. 70-85
- ^ Naturalis Historia, Book II, Chapter 6