Nobilus Danus
   Tyge (Latinized as Tycho) Brahe was born on December 14, 1546 at Knutstorps castle in Skåne county, Denmark (now part of Sweden).  He was the first son of Otto Brahe and Beatte Bille, both from noble Danish families with members in the Rigsraad.(5)  Hence his common epithet “nobilis Danus: The Noble Dane” applies literally.(15)  Otto made a deal with his more educated brother, Jörgen (Joergen), that if the child was born a boy, he could adopt and raise him.  However, when Tycho was, indeed born a boy, the father changed his mind and went back on his word.(7)  Later, when Otto and Beatte had another child, Jörgen kidnapped Tycho.  Hotheaded Otto threatened to kill his brother, but decided to let him have the child, since Tycho stood to inherit his uncle’s large estate.

   At age seven, Tycho began studying Latin.  His uncle insisted that the study would help him to become a lawyer or diplomat, typical occupations for members of nobility.  His parents objected, but the uncle prevailed.  In 1559, when he was thirteen, Brahe entered the University of Copenhagen to continue his law and philosophy studies.

   It was while in Copenhagen that Tycho was first intrigued by astronomy.  He witnessed a partial eclipse of the sun and, moreover, it had been predicted beforehand.  The eclipse occurred August 21, 1560, on schedule, striking him as “something divine that men should know the motions of the stars so accurately that they were able a long time beforehand to predict their places and relative positions.”(7,18)  With all the turmoil going on in his own life, it comes as no surprise that Brahe found the predictability of the stars appealing. 

Alfonsine tables
   The resources of his noble family proved advantageous, allowing little Tycho to buy himself a copy of Almagest, a book—written in Latin—by the infamous Alexandrian astronomer, mathematician, and geographer, Ptolemy (Claudius Ptolemaeus).  He also acquired some astronomical tables, which were supposed to predict the exact location of a planet at any given time.  Ptolemy made such astronomical tables that were eventually revised by Spanish astronomers under rule of Alfonso X of Castile in 1252.(7) Hence, they became known as the Alfonsine tables.  Young Tycho also purchased some more recent ones based on Copernicus’ relatively new theory.
   When he was sixteen, Tycho was sent by his uncle to the University of Leipzig, Germany, to continue his studies.  Twenty-year-old Anders Vedel (who later became famous as a Danish historian) tutored him in his study of law.  But when the tutor wasn’t around, Tycho snuck away and bought more astronomy books and measuring instruments.  With these, he stayed up late at night to observe the stars.  On August 17, 1563, he observed a unique event—Jupiter and Saturn passed by each other.  Brahe immediately realized that the Copernicus tables were off by several days and the Alfonsine tables were off by a month for their predictions of the event.  He was determined that better tables could be constructed by making more accurate observations of celestial objects over a long period of time.  It was then that he knew that he wanted to spend his life accomplishing that task.  He began by building his first astronomical instrument, a Jacob Stave.(9)  Simultaneously, Vedel gave up tutoring law to the “hopeless” boy, but the two remained friends for life.

Troubles
   In 1565 Tycho’s uncle Jörgen died unexpectedly.  King Frederik II had fallen into the moat of his castle after returning from a battle with Sweden.  The uncle, a popular but sometimes cruel, warship sailor was on the scene to rescue the king from drowning.  Unfortunately, the cold water gave Jörgen pneumonia that caused his death.
   Tycho returned to Denmark only to be greeted by a cold shoulder from his family.  They felt that his stargazing hobby was ruining his education of law (and they were right).  Once again, he left his unfriendly family for Germany.  Brahe studied at the University of Wittenberg, but left to avoid a plague.(5)  Later that year, he attended the University of Rostock.(6)  He persuaded some astronomers in Augsburg that more accurate astronomical observations were needed.  They made large instruments to record the locations of stars, but it would be a few decades until telescopes were available.  One wooden quadrant took twenty men to put together, and would have been part of a circle 38 feet across.  It was very precise, though, graduated to the minute (sixtieths of a degree).  This began Tycho’s legacy of accurate observations.
   During this stay in Rostock was an incident when Brahe expressed the short temper that he inherited from his father.  Tycho argued with another student and nobleman, Manderup Parsberg, over who was the better mathematician.  The two engaged in a duel with rapiers.  The tip of Tycho’s nose was cut off, and from then on he wore a silver and gold alloy in the vacated space.(7)  He was known to carry a snuffbox of  “ointment or glutinous composition” which was rubbed on his nose to keep the tip in place.

Tycho went home to recover from his dueling injury, but returned to Rostock in 1568.(5)  But, a few months later he left after getting fined for the duel.  He moved to the University of Basel for only a few months.  However, he liked the place and intended to move there eventually.

   In 1570, when Tycho was twenty-six, he went back to Denmark again.  He lived with his parents for a short while, then moved in with his maternal uncle, Steen Bille.  He was Tycho’s only relative who liked the star gazing ideas.  Steen was an entrepreneur who built the first paper mill and glassworks in Denmark.  Tycho occupied himself with chemistry for a while, with the help of Steen.  Meanwhile, he met Kirsten Jörgensdatter, a commoner and daughter of the priest in Kågeröd.  They were never officially married, but together they had five daughters and three sons.  The children were considered illegitimate under Danish custom, since his wife was a peasant.

De Nove Stella
   Brahe had another experience that changed his life, in 1572.  He was walking back from Steen’s alchemy lab on November 11 when he noticed an unusual star in the sky.(11)  Directly overhead, slightly northwest of Cassiopeia, was a star that shone brighter than Venus.(1) Tycho couldn’t believe his eyes.  He had servants confirm that the object was actually there.  Once again, his interest in astronomy was sparked by a celestial event.  The light remained in the sky for some eighteen months, sometimes shining bright enough to be seen in daylight.

   The object was, in fact, a rare “new” star, or nova (literally: nova means “new star”), as we know it today (we also know that novas are not new stars, but actually exploding stars).  Theologists and astronomers alike were curious about the object.  Was it in the sublunary region (below the moon), that is, a local phenomenon in the atmosphere?  It had to be or it would contradict the Aristotelian and Christian dogma—the eighth sphere (the fixed stars, the edge of heaven) supposedly hadn’t changed since creation.(7 ) Prominent astronomers Maestlin in Tübingen and Thomas Diggs in England tried to detect parallax (movement relative to other stars) of the object.  They used a primitive technique of lining up stretched threads along two known stars and the “new” star, but could detect no movement.  Tycho had just built a massive new sextant (with arms five and a half feet long), marked to the minute.  He even produced a table of corrections to compensate for any remaining miniscule errors that he detected that the instrument might make.  Then he settled the dispute by monitoring the star with his new equipment and found that it was completely stationary relative to the other stars.  This was some of the first evidence against the unchanging nature of the heavens—part of the firmament was actually changing before their eyes.(11)  Brahe hesitated about just what he should do with his findings, since it seemed rather improper for a nobleman to present such controversial ideas. The following year, he published a comprehensive description of his discovery—the object was, in fact, in the eighth sphere.

   His work, called De Nove et Nullius Aevi Memoria Prius Visa Stella (“On the New and Never Previously Seen Star”), published in 1574, made him famous throughout Europe.  That year he also taught astronomy lectures at the University of Copenhagen.(6)  In 1575 he set out on a tour to visit with astronomers around the continent.  Tycho then decided to move to Basle, Switzerland.  However, King Frederik II of Denmark (the one saved by Jörgen) couldn’t bear to lose the pride of Danish astronomy (and the king’s personal astrologer).  He offered Brahe a number of castles, but couldn’t convince him to stay.  Finally, in 1576, King Frederik offered him an island called Hveen (Hven) near Hamlet’s castle of Esinore.(7)  It was a nice, flat island with white cliffs about three miles across, located in Copenhagen sound between Denmark and Sweden.  The king promised to build an elaborate observatory and house there, and provide a stipend of 500 daler per year.  He also pledged to allow the people of a small village and some forty farms on the island to become Tycho’s subjects.  Denmark had just run across an abundance of resources when the Church’s wealth was turned over to the king during the Reformation.  Tycho couldn’t resist the offer, and thus became the first professional astronomer.(14)

The Lord of Uranienborg
   Tycho hired an architect from Germany and, on August 8th, the foundation was laid for his first observatory, Uranienborg (or Uraniborg, after Urania, the Goddess of the sky).  The building looked a lot like a castle, and its name even means “castle of the heavens.”  The ornate structure had an onion dome and an Italian style exterior.  A wall, 250 feet on each side and an elaborate garden surrounded the complex.  Inside there were rooms for his huge instruments, large murals, a paper mill and printing press, an alchemy laboratory in the basement, and even a prison for problematic tenants.(7)  He ordered a custom globe from Augsberg that was five feet across, made of polished brass.  It was placed in the library and the position of stars were precisely engraved on it throughout the twenty-five or so years that Brahe occupied Hveen.  One wall of his study had a giant quadrant built right into it.  There were clocks everywhere that were used to simultaneously time the meticulous observations that would take place at Uranienborg.  He had a large staff that allowed him to have an observer and a timekeeper work together at each instrument.  Several sets of equipment made it possible to make four independent measurements of the same object simultaneously. This was an integral part of the unprecedented accuracy achieved by Brahe.   

   The observatory was loaded with other contraptions—for example, he had a bell-ringing system to call servants in any room and there were statues that moved by hidden mechanisms.  Tycho was a heavy drinker who loved to throw magnificent parties and feasts for his visitors.  He would often entertain his guests with oddities, such as his tamed elk (unfortunately, it died one night when it fell down the stairs after having too much beer),(7) and a dwarf named Jepp,  who had an apparent sixth sense.(7)  Next to Uranienborg, Brahe built an underground observatory that he named Stjärneborg (Starry Castle).(15)  It had isolated observing stations that allowed multiple, independent measurements.

Tychonian Planetary Model
   Brahe was very productive during his years at Uranienborg.  He and his assistants tracked planets throughout the night, constantly recording measurements of their position.  Extensive observations were made for Mars, which would later prove crucial to his assistant, Johannes Kepler.  They made detailed records of the entire orbit of the planets.  Those observations lead to Brahe’s theory of the solar system.
In 1577, Tycho observed and recorded the path of a comet.  He measured the parallax, and was able to prove that the comet must be further away than the moon.(4)  Once again, he found himself contradicting the teachings of Aristotle.  Comets were explained as phenomena of burning gases in the atmosphere.  But Tycho showed that they actually weren’t in the atmosphere, but beyond.  This proved false the widely believed theory that planets were carried on huge crystal spheres—material spheres that wouldn’t allow a comet to pass through them.(6)  Comets couldn’t be described as either stars or planets (no circular motion), which lead to an interesting situation.
Brahe continued taking measurements to look for stellar parallax, but could find none.  Therefore, he concluded that either:  the earth was the center of the Universe, or stars were simply too far away to have a measurable parallax.(4)  He stuck with the wrong choice of this pivotal question, and thought that stars couldn’t possibly be that far away.  Thus, he felt that Nicolas Copernicus was wrong, and Tycho set out to develop his own planetary model.

   What he came up with was a compromise between the Ptolemaic (geocentric) and Copernican (heliocentric) models.  The Tychonian planetary model could best be described as geo/heliocentric.(14)  That is, planets rotated around the sun, but the sun and the moon rotated around earth.  His model became the most widely accepted for much of the 17th century.  Eventually, the Copernican model was proven correct, but Brahe’s observations were certainly a step in the right direction.

Astronomiae instauratae mechanica
   Tycho didn’t just observe the planets and comets.  He made a remarkable catalogue of over 1000 stars, many more than anyone had before him.(17)  He used a remarkable range of devices to record their precise locations.  Among them were ancient armillary spheres modeled after Ptolemy, sextants, and gigantic original quadrants made in his own workshops.  He even had a fresco in the observatory painted of him with his self-named instrument, the Tyconian Quadrant.  Measurements were consistently accurate to within 4’ (minutes) of an arc (1/15 of a degree), and some were twice that.(14,6)  Brahe was even the first to make corrections for atmospheric refraction.6  With his techniques, Brahe basically re-established observational astronomy.  He published (on his own paper and presses) the details of the findings from his observatories in a book, Astronomiae instauratae mechanica.  It became a model for other astronomers and astrologers, which lead to many improvements in stellar gadgetry.  In an attempt to convey astronomy as a noble occupation he wrote:
       The person who cultivates divine Astronomy ought not to be influenced by ignorant judgments, but rather     look upon them   from his elevated position, considering the cultivation of his studies the most precious of all        things, and remaining indifferent to the coarseness of others.  And when statesmen or others bother him too         much, then he should leave with his possessions.(15)

   Tycho ruled the island as a fiefdom and enjoyed his power, but eventually abused it.  He made the tenants work to provide supplies to which he wasn’t entitled, and chained them up if they didn’t concur.  But his luck ran out in 1588 when his friend, King Ferdinand II died of alcohol poisoning.  When his successor, King Christian IV, tried to make contact with Brahe, he never responded.  Tycho even defied the high court of justice by chaining up a tenant and his family.  This angered the new king, who reacted by cutting his income until Brahe eventually left Hveen in 1597.  All his equipment could be easily taken apart, as he said, “An astronomer must be…(mobile)…because ignorant statesmen cannot be expected to value their services.”(7)  The move would not be the end of him, though.   

On to Prague
   Brahe got his family, servants, instruments, and Jepp the dwarf together and searched across Europe for the location of his next observatory.  A short time later, Tycho offered to return to Denmark, once again, under terms more agreeable to him.  Christian IV basically responded, “Screw off,” so for a couple of years Tycho stayed in Wandsbech and other towns throughout Germany.  Leaving Denmark may have come as a blessing in disguise, though, because in 1599 he was appointed Imperial Mathematicus of Bohemia.  Emperor Rudolph II admired Tycho and offered him a castle of his choice plus a salary of 3,000 ducats a year.(2)
   Brahe chose the castle Benatky on the Jizera River, about 35 km from Prague.  Later he moved to the city, into the royal summer palace of Queen Anne.(10)  Living in Prague gave him the opportunity to take advantage of two inventors: Jost Burgi and Erasmus Habermel.  Burgi helped with calculations and Habermel helped with instruments, specifically a very precise sextant.  In 1600, he hired Johannes Kepler as his assistant to help with the mathematical calculations.  The two certainly didn’t agree on ideas, especially about the mechanics of the solar system.  Kepler was a convinced follower of Copernicus, while Brahe refused to accept the heliocentric theory.  But they worked well together, continuing the meticulous collection of data that made Tycho famous.

   Of course, working for royalty came with its downfalls.  Generally, astronomers were hired as astrologers to make predictions for the king.  However, one must note that Brahe was disgusted by astrological charlatans, and Kepler felt that the only influence of celestial bodies on earth was by the seasons and tides. But they did what was necessary to keep their ruler happy.  For example, Emperor Rudolf the II had Tycho make a list of days of bad luck.  They eventually became known as Tykobrahe days, and the Emperor watched them closely.  It is uncertain, however, just how Brahe came up with the days.(9)

   The next year was the last of Tycho’s life.  Supposedly, he died because he refused to leave a banquet in Prague to relieve himself.(4)  It was improper etiquette to get up from the table before the host left.  A few days later, on October 24, 1601, he died.(11)  Other sources suggest that mercury poisoning may have been the killer.19  Kepler recorded that his last words were “Ne frustra vixisse videar -May I not seemed to have lived in vain.”(17)  His tombstone can be found today at the Týn Church in Prague.  The epitaph (reportedly written by Brahe) reads, “He lived like a sage and died like a fool.”  Unfortunately, both his observatories at Hveen--Uranienborg and Stjärneborg--were destroyed shortly after his death, and his instruments from Prague were lost.