[hi-pahr-kuh
s] 
| 1. | died 514 b.c., tyrant of Athens 527–514. |
| 2. | c190–c125 b.c., Greek astronomer. |
| Hip·par·chus 1 (hĭ-pär'kəs) Athenian tyrant (527-514) who ruled with his brother Hippias and was assassinated. |
| Hip·par·chus 2 (hĭ-pär'kəs) Greek astronomer who mapped the position of 850 stars in the earliest known star chart. His observations of the heavens form the basis of Ptolemy's geocentric cosmology. |
| Hipparchus also Hipparchos (hĭ-pär'kəs) Pronunciation Key
Greek astronomer who mapped the positions of about 850 stars in the earliest known star chart (129 BCE). His observations of the heavens formed the basis of Ptolemy's Earth-centered model of the universe. He was also a pioneer of trigonometry. |