A postage stamp showing Uraniborg, an astronomical observatory operated by Tycho Brahe, along with Tycho's star, a supernova which flared in 1572. Tycho Brahe (1546-1601) was a Danish astronomer, astrologer 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. From there he generated the most accurate astronomical data of his time. 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.