Tycho Brahe

Tycho Brahe (1546–1601) was a Danish nobleman and the greatest astronomer of the age before the telescope. The solar eclipse of 1560 turned him to the stars. In 1566 a duel at Rostock cost him the bridge of his nose, and he wore a metal prosthesis thereafter.

In 1572 he saw a new star in Cassiopeia and found it lay beyond the Moon; he published De nova stella in 1573. Frederick II gave him the island of Hven, where he built Uraniborg and compiled the most accurate star catalogue yet made. He devised the Tychonic system, with the planets orbiting the Sun and the Sun orbiting the Earth.

In 1597 Christian IV forced him out of Denmark, and he became imperial astronomer in Prague. He died there in 1601, asking Johannes Kepler to finish the Rudolphine Tables; Kepler used his data to derive the laws of planetary motion.