Hipparchus

Hip·par·chus ¹  (h-pärks) Died 514 b.c.

Athenian tyrant (527-514) who ruled with his brother Hippias and was assassinated.

---

Hip·par·chus ²  (h-pärks) fl. second century b.c.

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 [hɪˈpɑːkəs]

n

(Astronomy) a large crater in the SW quadrant of the moon, about 130 kilometres in diameter

---

Hipparchus¹

n

1. (Biographies / Hipparchus (2nd century bc-2nd century bc) M, Greek, SCIENCE: astronomer) 2nd century bc, Greek astronomer. He discovered the precession of the equinoxes, calculated the length of the solar year, and developed trigonometry

2. (Biographies / Hipparchus (death date: 514 bc) M, Greeknational of birth: Athenian, POLITICS: tyrant) died 514 bc, tyrant of Athens (527-514)

---

Hipparchus also Hipparchos  (h-pärks) 190?-120? bce.

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.

Thesaurus

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)