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Tycho Brahe


Tycho Brahe (December 14, 1546 Knudstrup, Denmark – October 24, 1601 Prague, Bohemia (now Czech Republic)) was a Danish nobleman, well known as an astronomer/astrologer (the two were not yet distinct) and alchemist. He had Uraniborg built, which became an early "research institute ". For purposes of publication, Tycho owned a printing press and paper mill. His best known assistant was Johannes Kepler.


Early years

Tyge Brahe ('tee koh 'brah uh) (Tycho is the Latinised form he adopted at around age fifteen, and is someimes written Tÿcho) was born at his family's ancestral seat of Knudstrup Castle, Denmark to Otte Brahe and Beate Bille . His twin brother was stillborn (Tycho wrote a Latin ode (Wittendorf 1994, p. 68) to his dead twin which was printed as his first publication in 1572). He also had two sisters, one older (Kirstine Brahe ) and one younger (Sophie Brahe ). Otte Brahe, Tycho's father, a nobleman, was an important figure in the Danish King's court. Beate Bille, Tycho's mother, also came from an important family which had produced leading churchmen and politicians.

Tycho later wrote that when he was around two, his uncle, Jørgen Brahe , ... without the knowledge of my parents took me away with him while I was in my earliest youth. Apparently this did not lead to any disputes nor did his parents attempt to get him back. Tycho lived with his childless uncle and aunt, Jørgen Brahe and Inger Oxe , in the Tostrup Castle until he was six years old.

On April 19, 1559 Tycho began his studies at the University of Copenhagen. There, following the wishes of his uncle, he studied law but also studied a variety of other subjects and became interested in astronomy. It was, however, the eclipse which occurred on August 21, 1560, particularly the fact that it had been predicted, that so impressed him that he began to make his own studies of astronomy helped by some of the professors. He purchased an ephemeris and books such as Sacrobosco's Tractatus de Sphaera, Apianus ' Cosmographia seu descriptio totius orbis and Regiomontanus' De triangulis omnimodis.

I've studied all available charts of the planets and stars and none of them match the others. There are just as many measurements and methods as there are astronomers and all of them disagree. What's needed is a long term project with the aim of mapping the heavens conducted from a single location over a period of several years. -Tycho Brahe, 1563 (age 17).

Tycho realized that progress in the science of astronomy could be achieved not by occasional haphazard observations, but only by systematic and rigorous observation, night after night, and by using instruments of the highest accuracy obtainable. He was able to improve and enlarge the existing instruments, and construct entirely new ones. Tycho's naked eye measurements of planetary parallax were accurate to the arcminute. (These measurements became the possessions of Kepler following Tycho's death.)

While a student, Tycho lost part of his nose in a duel with broadswords with Manderup Parsberg, a fellow Danish nobleman. This occurred in the Christmas season of 1566, after a fair amount of drinking, while the just turned 20-year-old Tycho was studying at the University of Rostock in Germany. Attending a dance at a professor's house, he quarrelled with one Manderup Parsbjerg , a fellow member of the Danish gentry. A subsequent duel (in the dark) resulted in Tycho losing the bridge of his nose. A consequence of this was that Tycho developed an interest in medicine and alchemy. For the rest of his life, he was said to have worn a replacement made of silver and gold. Tycho's tomb was reopened in 1901 and his remains were examined by medical experts. The nasal opening of the skull was rimmed with green, a sign of exposure to copper, not silver or gold.

Family Life

In Knutstorp Tycho fell in love with Kirsten Jørgensdatter who was a commoner, her father, Pastor Jorgen Hansen, being the Lutheran clergyman of Knutstrop's village church. Under Danish law, when a nobleman and a commoner woman lived together openly as husband and wife, and she wore the keys to the household at her belt like any true wife, their alliance became a binding morganatic marriage after three years. The husband retained his noble status and privileges; the wife remained a commoner. Their children were legitimate in the eyes of the law, but they were commoners like their mother and could not inherit their father's name, coat of arms, or landed property. (Skautrup 1941, pp. 24-5)

Kirsten Jørgensdatter gave birth to their daughter, Kirstine (named after Tycho's late sister who died at 13) on October 12, 1573.


On November 11, 1572, Tycho observed (from Herrevad Abbey ) a very bright star which unexpectedly appeared in the constellation Cassiopeia. Since it had been maintained since Antiquity that the world of the fixed stars was eternal and unchangeable (a fundamental axiom of the Aristotelian world view, celestial immutability), other observers held that the phenomenon was something in the Earth's atmosphere. Tycho, however, observed that the parallax of the object did not change from night to night, suggesting that the object was far away. Tycho argued that a nearby object should appear to shift its position with respect to the background. He published a small book, De Stella Nova (1573), thereby coining the term nova for a "new" star. (We now know that Tycho's star was a supernova.) This discovery was decisive for his choice of astronomy as a profession.

Tycho's discovery was the inspiration for Edgar Allan Poe's poem, "Al Aaraaf".


Kepler tried, but was unable, to persuade Brahe to adopt the heliocentric model of the solar system. Tycho believed in a modified geocentric model known as the Tychonian system, for the same reasons that he argued that the supernova of 1572 was not near the Earth. He argued that if the Earth were in motion, then nearby stars should appear to shift their positions with respect to background stars. In fact, this effect of parallax does exist; it could not be observed with the naked eye, or even with the telescopes of the next two hundred years, because even the nearest stars are much more distant than most astronomers of the time believed possible.

Brahe and Astrology

Like the fifteenth century astronomer Regiomontanus, Tycho Brahe appears to have accepted astrological prognostications on the principle that the heavenly bodies undoubtedly influenced (yet did not determine) terrestrial events, but expressed skepticism about the multiplicity of interpretative schemes, and increasingly preferred to work on establishing a sound mathematical astronomy. Two early tracts, one entitled Against Astrologers for Astrology, and one on a new method of dividing the sky into astrological houses, were never published and are unfortunately now lost.

Tycho also worked in the area of weather prediction, produced astrological interpretations of the supernova of 1572 and the comet of 1577, and furnished his patrons Frederick II and Rudolph II with nativities and other predictions (thereby strengthening the ties between patron and client by demonstrating value.) An astrological worldview was fundamental to Tycho's entire philosophy of nature. His interest in alchemy, particularly the medical alchemy associated with Paracelsus, was almost as long-standing as his study of astrology and astronomy simultaneously, and Uraniborg was constructed as both observatory and laboratory.

In an introductory oration to the course of lectures he gave in Copenhagen in 1574, Tycho defended astrology on the grounds of correspondences between the heavenly bodies, terrestrial substances (metals, stones etc.), and bodily organs. He was later to emphasise the importance of studying alchemy and astrology together with a pair of emblems bearing the mottoes: Despiciendo suspicio - "By looking down I see upward" and Suspiciendo despicio - "By looking up I see downward." As several scholars have now argued, Tycho's commitment to a relationship between macrocosm and microcosm even played a role in his rejection of Copernicanism and his construction of a third world-system.

Uraniborg, Stjerneborg and Benátky nad Jizerou

King Frederick II of Denmark and Norway, impressed with Tycho's 1572 observations, financed the construction of two observatories for Tycho on the island of Hven in Copenhagen Sound. These were Uraniborg and Stjerneborg. Uraniborg also had a laboratory for Brahe's alchemical experiments.

Because he disagreed with Christian IV, the new king of his country, he moved to Prague in 1599. Sponsored by Rudolf II, the Holy Roman Emperor, he built a new observatory (in a castle in Benátky nad Jizerou 50 km away from Prague) and worked there until his death.

In return for their support, Tycho's duties included preparing astrological charts and predictions for his patrons on events such as births; weather forecasting; and astrological interpretations of significant astronomical events such as the comet of 1577 and the supernova of 1572.


Tycho was the preeminent observational astronomer of the pre-telescopic period, and his observations of stellar and planetary positions achieved unparalleled accuracy for their time. After his death, his records of the motion of the planet Mars enabled Kepler to discover the laws of planetary motion, which provided powerful support for the Copernican heliocentric theory of the solar system. Tycho himself was not a Copernican, but proposed a system in which the planets other than Earth orbited the Sun while the Sun orbited the Earth. This system is frequently described as a "compromise"; however, both the heliocentric and geocentric theories relied upon "crystal spheres", to which the planets were attached. Tycho's theory abandoned the crystal spheres, a remarkable step to take before Isaac Newton formulated the concept of "action at a distance". In this respect, then, the Tychonic universe was more revolutionary than the Copernican.

He was aware that a star observed near the horizon appears with a greater altitude than the real one, due to atmospheric refraction, and he worked out tables for the correction of this source of error.

Tycho's Death

Brahe died in 1601, several days after straining his bladder during a banquet. It has been said that to leave the banquet before it concluded, would be the height of bad manners and so he remained. His weakened state allowed an infection to invade his body and lead ultimately to his death.

Recent investigations suppose that Tycho did not die directly of his urinary problems, but may have poisoned himself unintentionally by administering some medicine containing mercury (he pursued alchemical studies as well throughout his life, however he seems either not to have kept records or to have destroyed them). [1]

Further reading

  • John Robert Christianson: On Tycho's Island: Tycho Brahe, science, and culture in the sixteenth century (Cambridge University Press, 2000) (ISBN 0-521-65081-X) (xii, 451 p. : ill., maps)
  • Mary Gow: Tycho Brahe : Astronomer (Berkeley Heights, NJ : Enslow Publishers, 2002) (ISBN 0766017575) (128 p. : ill.)
  • Victor E. Thoren: The Lord of Uraniborg: a biography of Tycho Brahe (Cambridge University Press, 1990) (ISBN 0-521-35158-8) (520pp)


  • Skautrup, Peter, 1941 Den jyske lov: Text med oversattelse og ordbog. Aarhus: Universitets-forlag.
  • Wittendorff, ALex. 1994. Tyge Brahe. Copenhagen: G. E. C. Gad.

External links

  • Astronomiae instauratae mechanica, 1602 edition
    - Full digital facsimile, Lehigh University.
  • Astronomiae instauratae mechanica, 1602 edition - Full digital facsimile, Smithsonian Institution.
  • Astronomiae instauratae mechanica, 1598 edition - Full digital facsimile, the Royal Library, Denmark. Includes Danish and English translations.

Named after Tycho

  • Tycho crater on the Moon.
  • Tycho Brahe crater on Mars.
  • An old name of an Irish synthpop band, now called Tychonaut.
  • Tycho Brahe, a character from the popular webcomic Penny Arcade.

Last updated: 02-06-2005 18:56:31
Last updated: 05-03-2005 17:50:55