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Tycho Brahe
Tycho Brahe ( TY-koh BRAH-(h)ee, -(h)ə); born Tyge Ottesen Brahe; generally called Tycho (14 December 1546 – 24 October 1601) was a Danish astronomer, known for his comprehensive astronomical observations, generally considered to be the most accurate of his time. He was known during his lifetime as an astronomer, astrologer, and alchemist. He was the last major astronomer before the invention of the telescope.
An heir to several noble families, Tycho was well-educated. He took an interest in astronomy and in the creation of more accurate instruments of measurement. He worked to combine what he saw as the geometrical benefits of Copernican heliocentrism with the philosophical benefits of the Ptolemaic system, and devised the Tychonic system, his own version of a model of the Universe, with the Sun orbiting the Earth, and the planets as orbiting the Sun. In De nova stella (1573), he refuted the Aristotelian belief in an unchanging celestial realm. His measurements indicated that "new stars" (stellae novae, now called supernovae) moved beyond the Moon, and he was able to show that comets were not atmospheric phenomena, as was previously thought.
King Frederick II granted Tycho an estate on the island of Hven and the money to build Uraniborg, the first large observatory in Christian Europe. He later worked underground at Stjerneborg, where he realised that his instruments in Uraniborg were not sufficiently steady. He treated the island residents as if he were an autocrat; they unsuccessfully sued him over their treatment. In 1597, he was forced by the new king, Christian IV, to leave Denmark. He was invited to Prague, where he became the official imperial astronomer, and built an observatory at Benátky nad Jizerou. Prior to his death in 1601, he was assisted for a year by Johannes Kepler, who went on to use Tycho's data to develop his own three laws of planetary motion.
Source: Wikipedia