4.9 Tycho brahe

Tyge (Latinized as Tycho) Brahe was born on 14 December 1546 in Skane, then in Denmark, now in Sweden. He was the eldest son of Otto Brahe and Beatte Bille, both from families in the high nobility of Denmark. He was brought up by his paternal uncle Jorgen Brahe and became his heir. He attended the universities of Copenhagen and Leipzig, and then traveled through the German region, studying further at the universities of Wittenberg, Rostock, and Basel. During this period his interest in alchemy and astronomy was aroused, and he bought several astronomical instruments. In a duel with another student, in Wittenberg in 1566, Tycho lost part of his nose. For the rest of his life he wore a metal insert over the missing part. He returned to Denmark in 1570.

In 1572 Tycho observed the new star in Cassiopeia and published a brief tract about it the following year. In 1574 he gave acourse of lectures on astronomy at the University of Copenhagen. He was now convinced that the improvement ofastronomy hinged on accurate observations. After another tour of Germany, where he visited astronomers, Tycho accepted anoffer from the King Frederick II to fund an observatory. He was given the little island of Hven in the Sont near Copenhagen,and there he built his observatory, Uraniburg, which became the finest observatory in Europe.

Tycho designed and built new instruments, calibrated them, and instituted nightly observations. He also ran his own printing press. The observatory was visited by many scholars, and Tycho trained a generation of young Sextantastronomers there in the art of observing. After a falling out with King Christian IV, Tycho packed up his instruments and books in1597 and left Denmark. After traveling several years, he settled in Prague in 1599 as the Imperial Mathematician at the court ofEmperor Rudolph II. He died there in 1601. His instruments were stored and eventually lost

Tycho's major works include De Nova et Nullius Aevi Memoria Prius Visa Stella ("On the New and Never Previously Seen Star) (Copenhagen, 1573); De Mundi Aetherei Recentioribus Phaenomenis ("Concerning the New Phenomena in the Ethereal World) (Uraniburg, 1588); Astronomiae Instauratae Mechanica ("Instruments for the Restored Astronomy") (Wandsbeck, 1598; English tr. Copenhagen, 1946); Astronomiae Instauratae Progymnasmata ("Introductory Exercises Toward a Restored Astronomy") (Prague 1602). His observations were not publishedduring his lifetime. Johannes Kepler used them but they remained the property of his heirs. Several copies in manuscriptcirculated in Europe for many years, and a very faulty version was printed in 1666. At Prague, Tycho hired Johannes Kepler asan assistant to calculate planetary orbits from his observations. Kepler published the Tabulae Rudolphina in1627. Because of Tycho's accurate observations and Kepler's elliptical astronomy, these tables were much more accurate thanany previous tables.