Tycho Brahe (December 14, 1546 - October 24, 1601) was a Danish astronomer and alchemist. After becoming interested in astronomy as a student in Copenhagen, Tycho Brahe realized the difficulty of making accurate measurements of celestial bodies with the instruments of the day. His designs for new methods and devices won him great fame. He was granted an estate on the island of Hven to conduct his research, and funding to built the Uraniborg observatory. As an astronomer he worked to combine the geometrical benefits of the Copernican system with the philosophical benefits of the Ptolemaic system into his own model of the universe, the Tychonic system. He was the last of the major naked eye astronomers, working without telescopes for his observations. Tycho is credited with the most accurate astronomical observations of his time, and the data was used by his assistant, Johannes Kepler, to derive the laws of planetary motion. No one before Tycho had attempted to make so many planetary observations. He was exiled to Prague in 1597 and was assisted in his work there by Johannes Kepler until his death. Due to a duelling injury at university, he always wore a metal nose prosthetic. In mid October of 1601 he contracted a bladder or kidney ailment after attending a banquet and died eleven days later at the age of 54.