Hipparchus

American  

[hi-pahr-kuhs] / hɪˈpɑr kəs /

noun

1. died 514 b.c., tyrant of Athens 527–514.

2. c190–c125 b.c., Greek astronomer.

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Hipparchus ¹ British  

/ hɪˈpɑːkəs /

noun

1. a large crater in the SW quadrant of the moon, about 130 kilometres in diameter

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Hipparchus ² British  

/ hɪˈpɑːkəs /

noun

1. 2nd century _bc , Greek astronomer. He discovered the precession of the equinoxes, calculated the length of the solar year, and developed trigonometry

2. died 514 _bc , tyrant of Athens (527–514)

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Hipparchus Scientific  

/ hĭ-pär′kəs /

1. 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.

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Example Sentences

Among other things, it was Hipparchus himself who first discovered Earth’s precession, and he modelled the apparent motions of the Sun and Moon.

From Scientific American • Oct. 20, 2022

The relationship between Hipparchus and Ptolemy has always been murky.

From Scientific American • Oct. 20, 2022

In his only surviving work, Hipparchus criticized earlier astronomical writers for not caring about numerical accuracy in their visions of orbits and celestial spheres.

From Scientific American • Oct. 20, 2022

Hipparchus, not having enough data on hand to solve the problem himself, had instead amassed observational material for posterity to use.

From Textbooks • Oct. 13, 2016

The figures, from left to right, are the astronomers Hipparchus, Copernicus, an anonymous ancient observer, Brahe and Ptolemy, each surrounded by symbols of his work.

From "The Invention of Science" by David Wootton