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Related to Hipparchus: Ptolemy
Hip·par·chus(hĭ-pär′kəs) fl. second century bc.
Greek astronomer who discovered the precession of the equinoxes, developed the techniques of trigonometry, and catalogued the positions of 850 stars in the earliest known star chart.
1. (Biography) 2nd century bc, Greek astronomer. He discovered the precession of the equinoxes, calculated the length of the solar year, and developed trigonometry
2. (Biography) died 514 bc, tyrant of Athens (527–514)
(Astronomy) a large crater in the SW quadrant of the moon, about 130 kilometres in diameter
1. died 514 B.C., tyrant of Athens 527–514.
2. c190–c125 B.C., Greek astronomer.
Second century b.c. Greek astronomer who mapped the position of 850 stars in the earliest known star chart. His observations of the heavens formed the basis of Ptolemy's Earth-centered model of the universe.
|Noun||1.||Hipparchus - Greek astronomer and mathematician who discovered the precession of the equinoxes and made the first known star chart and is said to have invented trigonometry (second century BC)|