The Greek astronomer Hipparchus (active 162-126 BC) discovered the precession of the equinoxes, founded trigonometry, and compiled the first star catalog. Born at Nicaea in Bithynia, Hipparchus studied astronomy, perhaps under Theodosius, and made some...

Hipparchus of Rhodes was a renowned Greek astrologer whose mathematical computations to chart the sun, moon, and stars led to his being named the founder of trigonometry. Hipparchus is also considered the founder of Greek astronomy for his systematic...

180-c. 126 B.C. Greek Astronomer, Geographer, and Mathematician Often described as the greatest astronomer of antiquity, Hipparchus (also known as Hipparchos, Hipparchus of Nicaea, or of Rhodes) revealed the precession of the equinoxes, determined the...

190-120 B.C. Greek astronomer sometimes credited as the father of trigonometry. Hipparchus discovered the precession of the equinoxes, or the shift in direction of Earth's axis of rotation, and produced a calculation of the year's length...

Hipparchus (Greek Ἵππαρχος; ca. 190 BC – ca. 120 BC) was a Greek astronomer, geographer, and mathematician of the Hellenistic period. Hipparchus was born in Nicaea (now Iznik, Turkey), and probably died on the island of Rhodes. He is...