## -0190 – Hipparchus – bio

Hipparchus was born around -0190 in Nicea, Greece, which is now part of Turkey. He was a mathematician and an accomplished astronomer who has generally been credited with observing and measuring the precession of the equinoxes, which is a small shift in the apparent position of stars that is caused by a wobble in the rotation of the Earth. He was one of the first astronomers to measure the elevation of a star above the horizon using an astrolabe. He collected an extensive “star catalog” of positional information.

Hipparchus is also known as the “father” of trigonometry. While Pythagoras, Euclid and Archimedes laid much of the foundations for trigonometry, Hipparchus was the first mathematician known to have created a table of trigonometric values that he used in his astronomical calculations.

PRECURSOR:

**-0575 – Pythagoras**

-0432 – Meton

-0408 – Eudoxus

**-0325 – Euclid**

**-0310 – Aristarchus**

**-0287 – Archimedes**

**-0276 – Eratosthenes**

SUBSEQUENT:

**0085 – Ptolemy**

0903 – Al-Sufi

**1473 – Copernicus**