He was known during his lifetime as an astronomer, astrologer , and alchemist. He was the last major astronomer before the invention of the telescope. Tycho Brahe has also been described as the greatest pre-telescopic astronomer. In , Tycho noticed a completely new star that was brighter than any star or planet.
Astonished by the existence of a star that ought not to have been there , he devoted himself to the creation of ever more accurate instruments of measurement over the next fifteen years β He later worked underground at Stjerneborg , where he realised that his instruments in Uraniborg were not sufficiently steady. His unprecedented research program both turned astronomy into the first modern science and also helped launch the Scientific Revolution.
An heir to several noble families, Tycho was well educated. 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 , 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. Prior to his death in , 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.
Tycho Brahe was born as heir to several of Denmark's most influential noble families. In addition to his immediate ancestry with the Brahe and the Bille families , he counted the Rud, Trolle , Ulfstand , and Rosenkrantz families among his ancestors. Both of his grandfathers and all of his great-grandfathers had served as members of the Danish king's Privy Council. His maternal grandfather, Claus Bille , lord to Bohus Castle and a second cousin of Swedish king Gustav Vasa , participated in the Stockholm Bloodbath on the side of the Danish king against the Swedish nobles.
