|Tycho Ottesen Brahe|
|Born||14 December 1546
Knutstorp Castle, Scania
|Died||24 October 1601 (aged 54)
|Spouse(s)||Kirstine Barbara Jørgensdatter|
|Parents||Otte Brahe and Beate Bille|
Tycho Brahe, born Tyge Ottesen Brahe (de Knudstrup) (14 December 1546 – 24 October 1601), was a Danish nobleman known for his accurate and comprehensive astronomical and planetary observations. Coming from Scania, then part of Denmark, now part of modern-day Sweden, Tycho was well known in his lifetime as an astronomer and alchemist.
His Danish name "Tyge Ottesen Brahe" is pronounced in Modern Standard Danish as [ˈtˢyːə ˈʌd̥əsn̩ ˈb̥ʁɑː]. He adopted the Latinized name "Tycho Brahe" (usually pronounced /ˈtaɪkoʊ ˈbrɑː/ or /ˈbrɑːhiː/ in English) from Tycho (sometimes written Tÿcho) at around age fifteen, and he is now generally referred to as "Tycho", as was common in Scandinavia in his time, rather than by his surname "Brahe". (The incorrect form of his name, Tycho de Brahe, appeared only much later.)
Tycho Brahe was granted an estate on the island of Hven and the funding to build the Uraniborg, an early research institute, where he built large astronomical instruments and took many careful measurements. After disagreements with the new king in 1597, he was invited by the Bohemian king and Holy Roman emperor Rudolph II to Prague, where he became the official imperial astronomer. He built the new observatory at Benátky nad Jizerou. Here, from 1600 until his death in 1601, he was assisted by Johannes Kepler. Kepler would later use Tycho's astronomical information to develop his own theories of astronomy.
As an astronomer, Tycho worked to combine what he saw as 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.
Tycho is credited with the most accurate astronomical observations of his time, and the data was used by his assistant Kepler to derive the laws of planetary motion. No one before Tycho had attempted to make so many planetary observations.
Tycho was born at his family's ancestral seat of Knudstrup Castle (Danish: Knudstrup borg; Swedish: Knutstorps borg), about eight kilometres north of Svalöv in then Danish Scania, now Swedish, to Otte Brahe and Beate Bille. His twin brother died before being baptized. Tycho wrote a Latin ode to his dead twin, which was printed in 1572 as his first published work. He also had two sisters, one older (Kirstine Brahe) and one younger (Sophia Brahe).
Otte Brahe, Tycho's father, was a nobleman and an important figure at the court of the Danish king. His mother, Beate Bille, came from an important family that had produced leading churchmen and politicians. Both parents are buried under the floor of Kågeröd Church, four kilometres east of Knutstorp. An epitaph, originally from Knutstorp, but now on a plaque near the church door, shows the whole family, including Tycho as a boy.
Tycho later wrote that when he was around age two, his uncle, Danish nobleman Jørgen Thygesen Brahe, "without the knowledge of my parents took me away with him while I was in my earliest youth to become a scholar". Apparently, this did not lead to dispute, nor did his parents attempt to get him back. According to one source, Tycho's parents had promised to hand over a boy child to Jørgen and his wife, who were childless, but had not honoured this promise. Jørgen seems to have taken matters into his own hands and took the child away to his own residence, Tosterup Castle. Jørgen Brahe inherited considerable wealth from his parents, which in terms of the social structure of the time made him eligible for a royal appointment as county sheriff. He was successively sheriff to Tranekjær (1542-49), Odensegaard (1549-52), Vordingborg Castle(1552-57), and finally (1555 until his death in 1565) to Queen Dorothea at Nykøbing Castle on Falster.
Tycho attended Latin school from ages 6 to 12, but the name of the school is not known. At age 12, on 19 April 1559, Tycho began studies at the University of Copenhagen. There, following his uncle's wishes, he studied law, but also studied a variety of other subjects and became interested in astronomy. The solar eclipse of 21 August 1560, especially the fact that it had been predicted, 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 on astronomy, including Johannes de Sacrobosco's De sphaera mundi, Petrus Apianus's Cosmographia seu descriptio totius orbis and Regiomontanus's De triangulis omnimodis. Jørgen Thygesen Brahe, however, wanted Tycho to educate himself in order to become a civil servant, and sent him on a study tour of Europe in early 1562. Tycho was given the young Anders Sørensen Vedel as mentor, whom he eventually talked into allowing the pursuit of astronomy during the tour. At age 17, Tycho wrote:
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 realized that progress in astronomy required systematic, rigorous observation, night after night, using the most accurate instruments obtainable. This program became his life's work. Tycho improved and enlarged existing instruments, and built entirely new ones. His sister Sophia assisted Tycho in many of his measurements. Tycho was the last major astronomer to work without the aid of a telescope, soon to be turned skyward by Galileo and others.
Tycho jealously guarded his large body of celestial measurements, which Kepler "usurped" following Tycho's death.
While studying at University of Rostock in Germany, on 29 December 1566 Tycho lost part of his nose in a duel with fellow Danish nobleman Manderup Parsbjerg. Tycho had earlier quarrelled with Parsbjerg at a wedding dance at professor Lucas Bacmeister's house on the 10th, and again on the 27th. The duel two days later (in the dark) resulted in Tycho losing the bridge of his nose. From this event Tycho became interested in medicine and alchemy. For the rest of his life, he was said to have worn a realistic replacement made of silver and gold, using a paste to keep it attached. Some people, such as Fredric Ihren and Cecil Adams have suggested that the false nose also had copper. Ihren wrote that when Tycho's tomb was opened in 24 June 1901 green marks were found on his skull, suggesting copper. Cecil Adams also mentions a green colouring and that medical experts examined the remains. Some historians have speculated that he wore a number of different prosthetics for different occasions, noting that a copper nose would have been more comfortable and less heavy than a precious metal one.
His uncle and foster father, Jørgen Brahe, died in 1565 of pneumonia after rescuing Frederick II of Denmark from drowning. In April 1567, Tycho returned home from his travels and his father wanted him to take up law, but Tycho was allowed to make trips to Rostock, then on to Augsburg (where he built a great quadrant), Basel, and Freiburg. At the end of 1570 he was informed about his father's ill health, so he returned to Knudstrup, where his father died on 9 May 1571. Soon after, his other uncle, Steen Bille, helped him build an observatory and alchemical laboratory at Herrevad Abbey.
Towards the end of 1571 Tycho fell in love with Kirsten, daughter of Jørgen Hansen, the Lutheran minister in Knudstrup. She was a commoner, and Tycho never formally married her. However, under Danish law, when a nobleman and a common 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 landholdings.
Kirsten Jørgensdatter gave birth to their first daughter, Kirstine (named after Tycho's late sister, who died at 13) on 12 October 1573. Together they had eight children, six of whom lived to adulthood. In 1574, they moved to Copenhagen where their daughter Magdalene was born. Kirsten and Tycho lived together for almost thirty years until Tycho's death.
Tycho was said to own one percent of the entire wealth of Denmark at one point in the 1580s and he often held large social gatherings in his castle. He kept a dwarf named Jepp (whom Tycho believed to be clairvoyant) as a court jester who sat under the table during dinner. Pierre Gassendi wrote that Tycho also had a tame moose (called an elk in Europe) and that his mentor the Landgrave Wilhelm of Hesse-Kassel (Hesse-Cassel) asked whether there was an animal faster than a deer. Tycho replied, writing that there was none, but he could send his tame elk. When Wilhelm replied he would accept one in exchange for a horse, Tycho replied with the sad news that the elk had just died on a visit to entertain a nobleman at Landskrona. Apparently during dinner the elk had drunk a lot of beer, fallen down the stairs, and died.
Tycho suddenly contracted a bladder ailment after attending a banquet in Prague, and died eleven days later, on 24 October 1601. According to Kepler's first hand account, Tycho had refused to leave the banquet to relieve himself because it would have been a breach of etiquette. After he had returned home he was no longer able to urinate, except, eventually, in very small quantities and with excruciating pain. The night before he died he suffered from a delirium during which he was frequently heard to exclaim that he hoped he would not seem to have lived in vain. Before dying, he urged Kepler to finish the Rudolphine Tables and expressed the hope that he would do so by adopting Tycho's own planetary system, rather than Copernicus's. A contemporary physician attributed his death to a kidney stone, but no kidney stones were found during an autopsy performed after his body was exhumed in 1901, and the modern medical assessment is that it is more likely to have resulted from uremia.
Recent investigations have suggested that Tycho did not die from urinary problems but instead from mercury poisoning—extremely toxic levels of it have been found in hairs from his moustache. The results were, however, not conclusive. Prague City Hall has approved a request by Danish scientists to exhume the remains. A team from Aarhus University was expected to arrive later this year and will have a week to work.
On 11 November 1572, Tycho observed (from Herrevad Abbey) a very bright star, now named SN 1572, which had unexpectedly appeared in the constellation Cassiopeia. Because it had been maintained since antiquity that the world beyond the Moon's orbit was eternally unchangeable (celestial immutability was a fundamental axiom of the Aristotelian world-view), other observers held that the phenomenon was something in the terrestrial sphere below the Moon. However, in the first instance Tycho observed that the object showed no daily parallax against the background of the fixed stars. This implied it was at least farther away than the Moon and those planets that do show such parallax. Moreover he also found the object did not even change its position relative to the fixed stars over several months as all planets did in their periodic orbital motions, even the outer planets for which no daily parallax was detectable. This suggested it was not even a planet, but a fixed star in the stellar sphere beyond all the planets. In 1573 he published a small book, De nova stella thereby coining the term nova for a "new" star (we now classify this star as a supernova and we know that it is 7500 light-years from Earth). This discovery was decisive for his choice of astronomy as a profession. Tycho was strongly critical of those who dismissed the implications of the astronomical appearance, writing in the preface to De nova stella: "O crassa ingenia. O caecos coeli spectatores" ("Oh thick wits. Oh blind watchers of the sky").
Tycho's discovery was the inspiration for Edgar Allan Poe's poem, "Al Aaraaf." In 1998, Sky & Telescope magazine published an article by Donald W. Olson, Marilynn S. Olson and Russell L. Doescher arguing, in part, that Tycho's supernova was also the same "star that's westward from the pole" in Shakespeare's Hamlet.
In 1574, Tycho published the observations made in 1572 from his first observatory at Herrevad Abbey. He then started lecturing on astronomy, but gave it up and left Denmark in spring 1575 to tour abroad. He first visited William IV, Landgrave of Hesse-Kassel's observatory at Kassel, then went on to Frankfurt, Basel and Venice. Upon his return he intended to relocate to Basel, but King Frederick II of Denmark, desiring to keep the distinguished scientist, offered Tycho the island of Hven in Oresund and funding to set up an observatory. Tycho first built Uraniborg in 1576 (with a laboratory for his alchemical experiments in its cellar) and then Stjerneborg in 1581. Unusual for the time, Tycho established Uraniborg as a research centre, where almost 100 students and artisans worked from 1576 to 1597.
After Frederick died in 1588 and his 11-year old son, Christian IV, succeeded him, Tycho's influence steadily declined. After several unpleasant disagreements, Tycho left Hven in 1597.
He moved to Prague in 1599. Sponsored by Rudolf II, Holy Roman Emperor, Tycho built a new observatory in a castle in Benátky nad Jizerou, 50 km from Prague, and worked there for one year. The emperor then brought him back to Prague, where he stayed until his death. Tycho received financial support from several nobles in addition to the emperor, including Oldrich Desiderius Pruskowsky von Pruskow, to whom he dedicated his famous "Mechanica". 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 supernova of 1572 (sometimes called Tycho's supernova) and the Great Comet of 1577.
Tycho's observations of stellar and planetary positions were noteworthy both for their accuracy and quantity. His celestial positions were much more accurate than those of any predecessor or contemporary. Rawlins (1993, §B2) asserts of Tycho's Star Catalog D, "In it, Tycho achieved, on a mass scale, a precision far beyond that of earlier catalogers. Cat D represents an unprecedented confluence of skills: instrumental, observational, & computational—all of which combined to enable Tycho to place most of his hundreds of recorded stars to an accuracy of ordermag 1'!"
He aspired to a level of accuracy in his estimated positions of celestial bodies of being consistently within 1 arcminute of their real celestial locations, and also claimed to have achieved this level. But in fact many of the stellar positions in his star catalogues were less accurate than that. The median errors for the stellar positions in his final published catalog were about 1'.5, indicating that only half of the entries were more accurate than that, with an overall mean error in each coordinate of around 2'. Although the stellar observations as recorded in his observational logs were more accurate, varying from 32.3" to 48.8" for different instruments, systematic errors of as much as 3' were introduced into some of the stellar positions Tycho published in his star catalog due, for instance, to his application of an erroneous ancient value of parallax and his neglect of polestar refraction. Incorrect transcription in the final published star catalogue, by scribes in Brahe's employ, was the source of even larger errors, sometimes by many degrees.
After his death, his records of the motion of the planet Mars provided evidence to support Kepler's discovery of the ellipse and area laws of planetary motion. Kepler's application of these two laws to obtain astronomical tables of unprecedented accuracy (the Rudolphine Tables) provided powerful support for his heliocentric model of the solar system.
Tycho himself was not a Copernican, but proposed a system in which the Sun and Moon orbited the Earth, while the other planets orbited the Sun. His system provided a safe position for astronomers who were dissatisfied with older models but were reluctant to accept the Earth's motion. It gained a considerable following after 1616 when Rome decided officially that the heliocentric model was contrary to both philosophy and Scripture, and could be discussed only as a computational convenience that had no connection to fact. His system also offered a major innovation: while both the geocentric model and the heliocentric model as set forth by Copernicus relied on the idea of transparent rotating crystalline spheres to carry the planets in their orbits, Tycho eliminated the spheres entirely.
Celestial objects observed near the horizon and above appear with a greater altitude than the real one, due to atmospheric refraction, and one of Tycho's most important innovations was that he worked out and published the very first tables for the systematic correction of this possible source of error. But as advanced as they were, they attributed no refraction whatever above 45 degrees altitude for solar refraction, and none for starlight above 20 degrees altitude.
To perform the huge number of multiplications needed to produce much of his astronomical data, Tycho relied heavily on the then-new technique of prosthaphaeresis, an algorithm for approximating products based on trigonometric identities that predated logarithms.
Kepler tried, but was unable, to persuade Tycho to adopt the heliocentric model of the solar system. Tycho believed in geocentrism because he held the Earth was just too sluggish to be continually in motion and also believed that if the Earth orbited the Sun annually there should be an observable stellar parallax over any period of six months, during which the angular orientation of a given star would change. This parallax does exist, but is so small it was not detected until the 1830s, when Friedrich Bessel discovered a stellar parallax of 0.314 arcseconds of the star 61 Cygni in 1838. Tycho advocated an alternative to the Ptolemaic geocentric system, a geo-heliocentric system now known as the Tychonic system. In such a system, the Sun annually circles a central Earth (regarded as essentially different from the planets), while the five planets orbit the Sun.
Tycho was not the first to propose a geoheliocentric system. It used to be thought that Heraclides in the 4th century BC had suggested that Mercury and Venus revolve around the Sun, which in turn (along with the other planets) revolves around the Earth. Ambrosius Theodosius Macrobius (395–423 AD) later described this as the "Egyptian System," stating that "it did not escape the skill of the Egyptians," though there is no other evidence it was known in ancient Egypt. The difference was that Tycho's system had all the planets (with the exception of Earth) revolving around the Sun, instead of just the interior planets of Mercury and Venus. In this regard, he was anticipated in the 15th century by the Kerala school astronomer Nilakantha Somayaji, whose geoheliocentric system also had all the planets revolving around the Sun. The difference to both these systems was that Tycho's model of the Earth does not rotate daily, as Heraclides and Nilakantha claimed, but is static.
Another crucial difference between Tycho's 1587 geo-heliocentric model and those of other geo-heliocentric astronomers, such as Paul Wittich, Reimarus Ursus, Helisaeus Roeslin and David Origanus, was that the orbits of Mars and the Sun intersected. This was because Tycho had come to believe the distance of Mars from the Earth at opposition (that is, when Mars is on the opposite side of the sky from the Sun) was less than that of the Sun from the Earth. Tycho believed this because he came to believe Mars had a greater daily parallax than the Sun. But in 1584 in a letter to a fellow astronomer, Brucaeus, he had claimed that Mars had been further than the Sun at the opposition of 1582, because he had observed that Mars had little or no daily parallax. He said he had therefore rejected Copernicus's model because it predicted Mars would be at only two-thirds the distance of the Sun. But he apparently later changed his mind to the opinion that Mars at opposition was indeed nearer the Earth than the Sun was, but apparently without any valid observational evidence in any discernible Martian parallax. Such intersecting Martian and solar orbits meant that there could be no solid rotating celestial spheres, because they could not possibly interpenetrate. Arguably this conclusion was independently supported by the conclusion that the comet of 1577 was superlunary, because it showed less daily parallax than the Moon and thus must pass through any celestial spheres in its transit.
Galileo's 1610 telescopic discovery that Venus shows a full set of phases refuted the pure geocentric Ptolemaic model. After that it seems 17th century astronomy then mostly converted to geo-heliocentric planetary models that could explain these phases just as well as the heliocentric model could, but without the latter's disadvantage of the failure to detect any annual stellar parallax that Tycho and others regarded as refuting it. The three main geo-heliocentric models were the Tychonic, the Capellan with just Mercury and Venus orbiting the Sun such as favoured by Francis Bacon, for example, and the extended Capellan model of Riccioli with Mars also orbiting the Sun whilst Saturn and Jupiter orbit the fixed Earth. But the Tychonic model was probably the most popular, albeit probably in what was known as 'the semi-Tychonic' version with a daily rotating Earth. This model was advocated by Tycho's ex-assistant and disciple Longomontanus in his 1622 Astronomia Danica that was the intended completion of Tycho's planetary model with his observational data, and which was regarded as the canonical statement of the complete Tychonic planetary system.
A conversion of astronomers to geo-rotational geo-heliocentric models with a daily rotating Earth such as that of Longomontanus may have been precipitated by Francesco Sizzi's 1613 discovery of annually periodic seasonal variations of sunspot trajectories across the sun's disc. They appear to oscillate above and below its apparent equator over the course of the four seasons. This seasonal variation is explained much better by the hypothesis of a daily rotating Earth together with that of the sun's axis being tilted throughout its supposed annual orbit than by that of a daily orbiting sun, if not even refuting the latter hypothesis because it predicts a daily vertical oscillation of a sunspot's position, contrary to observation. This discovery and its import for heliocentrism, but not for geo-heliocentrism, is discussed in the Third Day of Galileo's 1632 Dialogo. However, prior to that discovery, in the late 16th century the geo-heliocentric models of Ursus and Roslin had featured a daily rotating Earth, unlike Tycho's geo-static model, as indeed had that of Heraclides in antiquity, for whatever reason.
The fact that Longomontanus's book was republished in two later editions in 1640 and 1663 no doubt reflected the popularity of Tychonic astronomy in the 17th century. Its adherents included John Donne and the atomist and astronomer Pierre Gassendi.
The ardent anti-heliocentric French astronomer Jean-Baptiste Morin devised a Tychonic planetary model with elliptical orbits published in 1650 in a simplified, Tychonic version of the Rudolphine Tables. Some acceptance of the Tychonic system persisted through the 17th century and in places until the early 18th century; it was supported (after a 1633 decree about the Copernican controversy) by "a flood of pro-Tycho literature" of Jesuit origin. Among pro-Tycho Jesuits, Ignace Pardies declared in 1691 that it was still the commonly accepted system, and Francesco Blanchinus reiterated that as late as 1728. Persistence of the Tychonic system, especially in Catholic countries, has been attributed to its satisfaction of a need (relative to Catholic doctrine) for "a safe synthesis of ancient and modern". After 1670, even many Jesuit writers only thinly disguised their Copernicanism. But in Germany, Holland, and England, the Tychonic system "vanished from the literature much earlier".
James Bradley's discovery of stellar aberration, published 1729, eventually gave direct evidence excluding the possibility of all forms of geocentrism including Tycho's. Stellar aberration could only be satisfactorily explained on the basis that the Earth is in annual orbit around the Sun, with an orbital velocity that combines with the finite speed of the light coming from an observed star or planet, to affect the apparent direction of the body observed.
Tycho's distinctive contributions to lunar theory include his discovery of the Variation of the Moon's longitude. This represents the largest inequality of longitude after the equation of the center and the evection. He also discovered librations in the inclination of the plane of the lunar orbit, relative to the ecliptic (which is not a constant of about 5° as had been believed before him, but fluctuates through a range of over a quarter of a degree), and accompanying oscillations in the longitude of the lunar node. These represent perturbations in the Moon's ecliptic latitude. Tycho's lunar theory doubled the number of distinct lunar inequalities, relative to those anciently known, and reduced the discrepancies of lunar theory to about 1/5 of their previous amounts. It was published posthumously by Kepler in 1602, and Kepler's own derivative form appears in Kepler's Rudolphine Tables of 1627.
Although Tycho's planetary model was soon discredited, his astronomical observations were an essential contribution to the scientific revolution. The traditional view of Tycho is that he was primarily an empiricist who set new standards for precise and objective measurements. This appraisal originated in Pierre Gassendi's 1654 biography, Tychonis Brahe, equitis Dani, astronomorum coryphaei, vita. It was furthered by Johann Dreyer's biography in 1890, which was long the most influential work on Tycho. According to historian of science Helge Kragh, this assessment grew out of Gassendi's opposition to Aristotelianism and Cartesianism, and fails to account for the diversity of Tycho's activities.
Tycho considered astrology to be a subject of great importance. In addition to his contributions to astronomy, he was famous in his own time also for his contributions to medicine; his herbal medicines were in use as late as the 1900s. Although the research community Tycho created in Uraniborg did not survive him, while it existed it was both a research center and an institution of education, functioning as a graduate school for Danish and foreign students in both astronomy and medicine. Tycho's success as a scientist also depended on his adroit political skills, to obtain patronage and funding for his work.
TYCHO BRAHE (1546-1601), Danish astronomer, was born on the 14th of December 1546 at the family seat of Knudstrup in Scania, then a Danish province. Of noble family, he was early adopted by his uncle, Jdrgen Brahe, who sent him, in April 1559, to study philosophy and rhetoric at Copenhagen. The punctual occurrence at the predicted time, August 21 st, 1560, of a total solar eclipse led him to regard astronomy as "something divine"; he purchased the Ephemerides of Johann Stadius (3rd ed., 1570), and the works of Ptolemy in Latin, and gained some insight into the theory of the planets. Entered as a law-student at the university of Leipzig in 1562, he nevertheless secretly prosecuted celestial studies, and began continuous observations with a globe, a pair of compasses and a "cross-staff." He quitted Leipzig on the 17th of May 1565, but his uncle dying a month later, he repaired to Wittenberg, and thence to Rostock, where, in 1566, he lost his nose in a duel, and substituted an artificial one made of a copper alloy. In 1569 he matriculated at Augsburg, and devoted himself to chemistry for two years (1570-1572). On his return to Denmark, in 1571, he was permitted by his maternal uncle, Steno Belle, to instal a laboratory at his castle of Herritzvad, near Knudstrup; and there, on the 11th of November 1572, he caught sight of the famous "new star" in Cassiopeia. He diligently measured its position, and printed an account of his observations in a tract entitled De Nova Stella (Copenhagen, 1 573), a facsimile of which was produced in 1901, as a tercentenary tribute to the author's memory.
Tycho's marriage with a peasant-girl in 1573 somewhat strained his family relations. He delivered lectures in Copenhagen by royal command in 1574; and in 1575 travelled through Germany to Venice. The execution of his design to settle at Basel was, however, anticipated by the munificence of Frederick II., king of Denmark, who bestowed upon him for life the island of Hveen in the Sound, together with a pension of 500 thalers, a canonry in the cathedral of Roskilde, and the income of an estate in Norway. The first stone of the magnificent observatory of Uraniborg was laid on the 8th of August 1576; it received the finest procurable instrumental outfit; and was the scene, during twenty-one years, of Tycho's labours in systematically collecting materials - the first made available since the Alexandrian epoch - for the correction of astronomical theories. James VI. of Scotland, afterwards James I. of England, visited him at Uraniborg on the 20th of March 1590. But by that time his fortunes were on the wane; for Frederick II. died in 1588, and his successor, Christian IV., was less tolerant of Tycho's arrogant and insubordinate behaviour. His pension and fief having been withdrawn, he sailed for Rostock in June 1597, and re-commenced observing before the close of the year, in the castle of Wandsbeck near Hamburg. He spent the following winter at Wittenberg, and reached Prague in June 1J99, well assured of favour and protection from the emperor Rudolph II. That monarch, accordingly, assigned him the castle of Benatky for his residence, with a pension of 3000 florins; his great instruments were moved thither from Hveen, and Johannes Kepler joined him there in January 1600. But this phase of renewed prosperity was brief. After eleven days' illness, Tycho Brahe died on the 24th of October 1601, at Benatky, and was buried in the Teynkirche, Prague.
Tycho's principal work, entitled Astronomiae Instauratae Progymnasmata (2 vols., Prague, 1602-1603) was edited by Kepler. The first volume treated of the motions of the sun and moon, and gave the places of 777 fixed stars (this number was increased to 1005 by Kepler in 1627 in the "Rudolphine Tables"). The second, which had been privately printed at Uraniborg in 1588 with the heading De Mundi Aetherei recentioribus Phaenomenis, was mainly concerned with the comet of 1577, demonstrated by Tycho from its insensible parallax to be no terrestrial exhalation, as commonly supposed, but a body traversing planetary space. It included, besides, an account of the Tychonic plan of the cosmos, in which a via media was sought between the Ptolemaic and Copernican systems. The earth retained its immobility; but the five planets were made to revolve round the sun, which, with its entire cortege, annually circuited the earth, the sphere of the fixed stars performing meanwhile, as of old, its all-inclusive diurnal rotation (see Astronomy: History). Under the heading Astronomiae Instauratae Mechanica, Tycho published at Wandsbeck, in 1598, a description of his instruments, together with an autobiographical account of his career and discoveries, including the memorable one of the moon's "variation" (see MooN). The book was reprinted at Nuremberg in 1602 (cf. Hasselberg, Vierteljahrsschrift Astr. Ges. xxxix. iii. 180). His Epistolae Astronomicae, printed at Uraniborg in 1596 with a portrait engraved by Geyn of Amsterdam in 1586, were embodied in a complete edition of his works issued at Frankfort in 1648. Tycho vastly improved the art of astronomical observation. He constructed a table of refractions, allowed for instrumental inaccuracies, and eliminated by averaging accidental errors. He, moreover, corrected the received value of nearly every astronomical quantity; but the theoretical purpose towards which his practical reform was directed, was foiled by his premature death.
See J. L. E. Dreyer's Tycho Brahe (Edinburgh, 1890), which gives full and authentic information regarding his life and work. Also Gassendi's Vita (Paris, 1654); Lebensbeschreibung, collected from various Danish sources, and translated into German by Philander von der Weistritz (Copenhagen and Leipzig, 1756); Tyge Brahe, by F. R. Friis (Copenhagen, 1871); Prager Tychoniana, collected by Dr F. I. Studnicka (Prague, 1901), a description of the scanty Tychonian relics which survived the Thirty Years' War and are still preserved at Prague. (A. M. C.)
Tycho Brahe (info • help), born as Tyge Ottesen Brahe, (lived December 14 1546 – October 24 1601), was an astronomer from Denmark who built a big observatory called Uraniborg on a place called Hven in Denmark. He discovered that the universe besides the solar system was always changing. Johannes Kepler was his helper.