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

The relationship between Hipparchus and Ptolemy has always been murky.

From Scientific American • Oct. 20, 2022

And whereas Ptolemy based his coordinate system on the ecliptic, Hipparchus used the celestial equator, a system more common in modern star maps.

From Scientific American • Oct. 20, 2022

Several lines of evidence point to Hipparchus as the source, beginning with the idiosyncratic way in which some of the data are expressed.

From Scientific American • Oct. 20, 2022

As we saw Observing the Sky: The Birth of Astronomy, astronomical photometry began with Hipparchus.

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