Tycho Brahe

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Tycho Brahe with the Elephant Order
Signature Brahe: Tÿcho Brahe

Listen to Tycho Brahe ? / i ( Tyge Ottesen Brahe , also known as Tycho de Brahe ; * December 14, 1546 at Knutstorp Castle , Skåne , then Denmark ; † October 24, 1601 in Prague or in Benátky near Prague , Kingdom of Bohemia ) was a Danish nobleman and one of the greatest astronomers . The extent, the care and the accuracy of his astronomical observations, which he carried out without telescopes , were astonishing for the time. He thus had a decisive influence on the scientific ideal of later generations and founded the working style and methodology of modern science with his working method of increasingly precise measurement and constant checking. Audio file / audio sample



The tychonic worldview according to Brahe in a representation by Andreas Cellarius in 1708
Tycho Brahe's tomb in the Tyn Church in Prague

Tycho Brahe was of noble descent. On April 19, 1559, at the age of 12, he was enrolled at the University of Copenhagen . This was followed - as was customary at the universities influenced by the Reformation at the time - the propaedeutic study of the Artes Liberales , consisting of the subjects of grammar, dialectics, rhetoric (trivium) and arithmetic, geometry, music, astronomy (quadrivium). A solar eclipse in 1560 sparked Tychos' great interest in astronomy, and so he began to delve into this subject. He read every book he could get and kept stargazing. In the following years he continued his studies at the universities of Leipzig , Wittenberg , Rostock and Basel . In Leipzig he began studying astronomy with Johannes Hommel and later with Valentin Thau . Inadequate observation methods of the observatories at that time meant that he dealt early on with the methodology and the instruments for measuring the height of the celestial body positions.

At the age of 20 Brahe lost a large part of his nose to his cousin Manderup Parsberg in a duel in Rostock , the reason for which was the dispute over a mathematical formula . According to tradition, he wore a nose prosthesis made of a gold - silver alloy, which he glued on with an ointment. However, when his grave was opened in 1901 and the skull was examined in order to find evidence of the aforementioned prosthesis, residues of copper salts were found at the corresponding point, which indicated a thin copper foil rather than a more difficult-to-wear prosthesis made of a gold alloy.

Brahe and his sister Sophie Brahe observed a supernova in 1572 , “a miracle that has not been seen since the beginning of the world”. His writing on the "new, never-before-seen star" made him famous among astronomers across Europe.

In 1573 he married a commoner: Kirstine Barbara Jörgensdatter, according to the sources a daughter of the pastor of Kågeröd . They had eight children, other scriptures name nine.

Tychos Wall Quadrant, 1598

King Frederick II of Denmark and Norway financed the Uraniborg and Stjerneborg observatories on the then still Danish Öresund island of Ven off Landskrona , on which Brahe researched for 21 years. Brahe not only built all of the instruments he needed, but also printed his own books.

Tycho Brahe was an outstanding observing astronomer. In his day there was no telescope . He carried out his observations of the fixed star and planetary positions , which were by far the most precise at the time and are still not easily accessible today with an accuracy of two arc minutes , with the help of a large quadrant of the wall . Due to the contradictions of the planetary movements in the then dominant world systems, he developed a compromise between the Ptolemaic-geocentric and the Copernican-heliocentric planetary system , which was called the tychonic worldview .

After the death of Frederick II in 1588, his successor King Christian IV cut financial resources, which is why Brahe moved into one of his manor houses, the Wandesburg near Hamburg , at the invitation of his friend Heinrich Rantzau in October 1597 .

In September 1598 Brahe left Wandsbek with his sons and students and moved to Prague in 1599 . Emperor Rudolf II had offered him a position as court mathematician and wanted to have a new observatory built for him there. However, construction was not completed until after Brahe's death.

Brahe stayed from August 1599 to June 1600 in the quieter town of Benátky nad Jizerou (Venice on the Jizera) . He died in Prague in 1601. His wife Kirstine bought an estate in Bohemia , which she lived in for three years until her death. Tycho and Kirstine Brahe were buried side by side in the Tyn Church in Prague.

The Augsburg Quadrant

On his travels through Europe, Tycho Brahe came to Augsburg in 1568. He spent almost three years observing the stars here and one day also met the Augsburg patrician, mayor and enthusiastic astronomer Paul Hainzel . Hainzel was fascinated by the idea of ​​a large precision instrument with unprecedented accuracy. In 1570 he had Brahe make a huge quadrant with a radius of 6.4 meters from oak wood in Göggingen south of Augsburg at his own expense . Due to its size, the brass scale could be accurately divided to ten arc seconds. Brahe himself did not, however, make any observations with the quadrant; he had already left Augsburg. The Augsburg Quadrant was destroyed by a storm four years later.

The 1572 supernova

On the evening of November 11, 1572, Tycho Brahe saw a star in the constellation Cassiopeia - as bright as Venus - that did not belong there. It couldn't be a fixed star , because the fixed star sky was eternal and unchangeable, according to the ancient belief of that time. It couldn't be a planet either, because it showed no change in location. A year after the star appeared, it finally faded. The event caused a great sensation in wide circles. Brahe wrote De nova et nullius ævi memoria prius visa Stella , in which he described his observations. From the immutability of the position of the new star, he boldly concluded that it must belong to the sphere of fixed stars. His writing, with which he not only contradicted Aristotle but also refuted him, made him known among astronomers all over Europe and opened all doors for him. A supernova had been observed by the Chinese as early as 1054 , but the medieval European scholastic scholars were unaware of it.


Uraniborg castle (without outbuildings) and gardens

Brahe made trips throughout Europe to his training in the jurisprudence to complete. But he also used these trips to meet as many astronomers as possible. Brahe was convinced that in the age in which he lived, scientific progress in astronomy was only possible through the most careful observation and recording of the numbers and data. This was an unusual view at the time, as divine inspiration was the only form of knowledge. How should one "be able to experience the why by measuring how much", one wondered. So he also came to Kassel to see Landgrave Wilhelm IV , who was enthusiastic about astronomy , who obviously recognized Brahe's special talent and made Frederick II of Denmark aware of Brahe - reason enough for the king, Tycho Brahe, to observe the Öresund island of Ven for life To make available. In addition, he took over all costs for necessary instruments, buildings and staff, which after all made up 1–2% of the royal income. In August 1576 the foundation stone was laid for one of the most famous observatories of all time. It was completed in 1580.

Brahe called his research facility in accordance with Urania , the muse of astronomy from the Greek mythology , Uraniborg . Due to his ingenuity, his powers of observation and Friedrich's generous financial support, it became the most important observatory of the time, a knowledge factory for observational astronomy. It not only contained the various buildings, living quarters and library rooms required for the instruments, but also farm buildings, a chemical laboratory, mechanical workshops and handicrafts, as well as its own printing press and even a specially built paper mill. From building your own instruments to observing the stars at night to printing research results - everything was at home on Uraniborg .

The comet of 1577

Uraniborg Castle, from Joan Blaeu : The Great Atlas , 1663

During the construction of Uraniborg , the comet of 1577 kept astronomers busy .

Uraniborg was already partially operational, and Brahe also turned to the new object in the sky. A  discussion by letter and an exchange of observational results between the astronomers developed - aided by the long duration of the comet's visibility . Brahe was particularly interested in the parallax of the comet, i.e. the apparent change in position of an object on the fixed star background when the observer shifts his position. Because comets were not considered celestial bodies in his time and before, but were taken for mere appearances or "atmospheric disturbances" within the so-called sublunar region of the sky . According to the generally accepted doctrine, changes could only take place in this area. But Brahe was a neutral observer, he checked all available measurements - his own and those of his colleagues - again and again. The result was clear to him: the comet could not be part of the sublunar region, but had to be far outside the atmosphere due to the lack of parallax, i.e. part of the planetary sky. Even more: the comet moved in such a way that it inevitably had to penetrate the planetary spheres, but it was not possible to measure any inhibition of movement by these planet-bearing shells.

From then on, Tycho Brahe saw comets as part of the planetary framework, and his doubts about the Ptolemaic view of the world grew . However, his knowledge did not take hold immediately, even half a century later even Galileo scoffed at the "Tychonic ape planets" when he meant comets. Only Johannes Kepler recognized the true meaning of this discovery: planets and comets as freely moving bodies in space.


Stjerneborg observatory not far from Uraniborg

Tycho Brahe soon discovered that Uraniborg was not big enough for his newly designed precision instruments and that it was also unstable on sandy ground. In addition, because of the temperature fluctuations and winds, observations above ground gave less good results than an underground observatory. In 1584, for example, he built a second, now underground, observatory on Ven, 100 meters south of Uraniborg, and named it Stjerneborg ( German:  Star Castle ) with partly half and partly completely sunk observation rooms. Above the north entrance, Brahe had a motto carved in stone:


"Neither high offices nor power, only the sceptres of science survive"

Sophie Brahe , Tycho's younger sister, often worked with her brother against all convention. At the time he left for college, she was still a small child and had acquired a knowledge of astronomy on her own. Together they carried out sky observations in Uraniborg and wrote a new catalog of fixed stars of a thousand star locations.

With the death of his patron Frederick II in 1588 and the appointment of Christian IV as the new king, Brahe's influence at the royal court waned and his budget was cut several times. So in 1597 he decided to leave Ven for Holstein after 21 years . He took all of the instruments he had built in Uraniborg with him.

Meeting with Johannes Kepler

Benatek Castle, where Brahe and Kepler first met

Tycho Brahe was impressed by the wealth of ideas in Kepler's first work Mysterium Cosmographicum (World Secret), but rejected the results based on Copernicus. He invited Johannes Kepler to Prague. He hoped that with the help of his own decade-long precision observations, Kepler's inspiration and theoretical, especially mathematical skills, he would succeed in making the tychonic system a breakthrough.

They met for the first time on February 4, 1600 at Benatek Castle , not far from Prague , where Brahe was residing at the time. Kepler lived and worked there too. The collaboration turned out to be extremely difficult, both characters were too different. Brahe, rather irascible and domineering, often made work difficult for the sensitive Kepler, who was 25 years his junior. However, Kepler recognized the great importance of Brahe's extensive observations, but he made just as much of them available as Kepler absolutely needed to work on the tasks set by Brahe. But Kepler recognized the gaps in the columns of figures and tables and confronted Tycho Brahe about them.


The circumstances of Brahe's death were bizarre and the cause of death long unclear. On October 13, 1601, he took part in a banquet given by Emperor Rudolph II . According to tradition, he had to leave the table early because of severe bladder pain. The reason for this was suspected to be a rupture of the bladder caused by retention of urine , possibly as a result of court etiquette that forbade guests to rise from the table in front of the emperor. Brahe died ten days later after suffering serious illness.

Brahe's closest friend, the famous doctor and anatomist Jan Jessenius , described the course of the illness in his last days in such a way that Brahe finally arranged a lot of things with great clarity and said goodbye to everyone. Among other things, he stipulated that after his death Johannes Kepler should go through all of his scientific documents in order to finalize them. Kepler followed his request and published the collected data and results under Tycho Brahe's name.

The funeral speech for Tycho Brahe was given by Jan Jessenius. Brahe's tomb is located in the Tyn Church on the Old Town Square in Prague. In addition to Brahe's motto mentioned above, there is also the inscription: ESSE POTIUS QUAM HABERI (“To be is more than appearing”).

Brahe's tomb in Prague

Research in the 1990s on hair samples obtained from an exhumation in 1901 revealed a high concentration of mercury that could have been fatal. Several hypotheses could explain how they came about : either Brahe had taken a remedy containing mercury , or it was a consequence of poisoning from handling chemicals. The toxicity of mercury was not yet known at the time; Medicines containing mercury were widespread at the time.

Against the background of the unexplained cause of death, the 2004 poison murder story by the journalist couple Joshua and Anne-Lee Gilder gained a certain amount of attention. In her book, Kepler is described as a murderer with a devious character. The German Kepler Society issued a statement in 2005 in which the Gilders' poison murder story is presented as "absurd and absurd".

On November 15, 2010, Tycho Brahe's grave was reopened in the Teynkirche. A research team led by Kaare Lund Rasmussen ( Syddansk Universitet ) and Jan Kučera (Nuclear Physics Institute of the Academy of Sciences of the Czech Republic ) examined hair and bone samples to clarify the cause of Brahe's death. In November 2012 it was finally announced that mercury poisoning could be ruled out as the cause of death. The likely cause is a severe bladder infection.

Kepler as Brahe's legacy

Title page of the Rudolfinian tablets

After Brahe's death in October 1601, Kepler, who had recently become his assistant, was appointed his successor at the court of Rudolph II. With that, a weighty, still incomplete work was passed on to Kepler: the Rudolphine tables, which were commissioned by the emperor . They were supposed to replace the Alfonsine and the newer Prutenic tables .

Kepler finally received all of Brahe's observational data, especially those of the planet Mars , which Brahe had observed intensively and over a long period of time. Finally in possession of the indispensable observation treasure, Kepler realized that the position data of the planet Mars deviated from the Copernican, circular orbit by eight arc minutes (this corresponds to about ¼ full moon diameter). These inconspicuous eight minutes of arc showed Kepler the right way to abandon the concept of circular orbits that had been valid for almost 2000 years. With the help of Brahe's observations, Kepler was finally able to demonstrate the elliptical orbital motion of the planet Mars (later also of the other planets) and even calculate the planet's speed precisely (three Kepler's laws ).

Brahes instruments

Tycho Brahe's research marks the end and the climax of a nearly 2000 year long period of systematic sky observation that had to do without the invention of the lens . Brahe's instruments are characterized by the use of the sighting principle. In Kassel with Landgrave Wilhelm IV. He had studied his all-metal instruments and recognized the processing possibilities of metal with regard to the smallest possible tolerances. In addition, the measurement accuracy of all scales could be increased in a simple way: the larger the scale, the more precisely one could read the instruments. So he decided to build the largest and most precise astronomical instruments that had been designed up to that point.

An armillary sphere according to Tycho Brahe

Brahe built a good dozen instruments in Uraniborg. One of the best known and most precise was the wall quadrant , also called the tychonic quadrant, with a radius of two meters. It was firmly installed on a wall and facing exactly south. He used a special kind of transversely rasterized zigzag lines on the inside of the quadrant. This made it possible to achieve declination resolutions of ten arc seconds.

Another well-known instrument was a huge iron armillary sphere 2.9 meters in diameter. It was used by Brahe for the precise measurement of coordinates in the sky and the representation of the movement of celestial bodies. Other devices included various portable quadrants and smaller armillary spheres, as well as a number of astronomical sextants and triquetres .

Brahe was also one of the first scientists to recognize the value of multiple observations. He therefore employed a permanent team of employees who all observed the same event with different instruments at the same time. However, the simplest principles of error calculation were still unknown. What seems easy to us today were laborious conversions of the spherical trigonometry , which often gave a more than uncertain result. Nevertheless, Brahe succeeded with perseverance and care to obtain results with an accuracy of 2 arc minutes and thus to improve the information previously used by Claudius Ptolemy by about ten times.

Soon after Tycho Brahe's death, a new era began in astronomy with the invention of the telescope by Hans Lipperhey in 1608. Working with the extensive range of instruments ended with his death. The valuable equipment was partly destroyed in subsequent wars, carried off as spoils of war or rotted away in underground vaults, to which Emperor Rudolf II in Prague had them brought for better safety. Only the large armillary sphere took an adventurous journey through a Jesuit monastery in Silesia and from there back to the Royal Academy of Copenhagen, where it burned in the great conflagration of 1728.

Nevertheless, Brahe's observational data, as the most reliable, remained indispensable for many decades.

Brahe's world system

World system according to Paul Wittich and Tycho Brahe: In the center of the world is the earth, but the other planets move around the sun

Brahe mistrusted the heliocentric worldview of Nicolaus Copernicus . In a letter to the mathematician Christoph Rothmann , who was in the service of Wilhelm IV, he raised the following objection to the earth's movement: “If the earth actually rotates from west to east, then a cannonball must be shot in the direction of the earth's rotation , fly much further than a projectile fired in the opposite direction. ”Rothmann replied that both the projectile and the cannon take part in the earth's movement and that his objection is therefore invalid. However, this contradicted the then valid Aristotelian view of movement. On the other hand, as a precision observer, Brahe knew the shortcomings of the old Ptolemaic-geocentric world system, especially the problems of the epicyclic theory .

Brahe developed a compromise proposal, his own system known as the Tychonic World Model , which combined Ptolemaic-geocentric and Copernican-heliocentric aspects and, in his opinion, represented the facts better: In the center, as in the Ptolemaic worldview, rests the earth. The moon and sun revolve around them, but all other celestial bodies move around the sun as in Copernicus. Only the sphere with the fixed stars moves around the earth once every 24 hours. This should eliminate a large part of the problems of epicyclic theory. Tycho Brahe saw it as his life's task to prove this world system with ever more precise observations, but he himself did not work out a theory of motion because of his limited mathematical skills. Against this background, his worldview is more comparable with the observation-based systems of thought of Eudoxus or Aristarchus of Samos than with the theory-based systems of Claudius Ptolemy or Copernicus .

In fact, it was not until 1851 that Léon Foucault succeeded in using the so-called Foucault pendulum experiment to prove the rotation of the earth and thus refute the Brahe world system. Up until then, all observations such as those of the four Venus phases were also compatible with Brahe's world model.

A dispute arose over the authorship of his world system with the astronomer Nicolaus Reimers , who was also friends with Heinrich Rantzau and had visited Brahe in Uraniborg . The central role of Paul Wittich was examined by Owen Gingerich .


Brahe's achievements

Above all, Brahe was an observer. His instruments, which were built according to his instructions and were excellent for the time, and the staffing of the observatories at his disposal were important prerequisites for his success as an astronomer.

Brahe amassed a vast amount of observation material. The care and accuracy of his observations were astounding. By observing the sun and simply bearing using the sighting principle over the rear sight and front sight, he was able to determine the length of the year significantly better, which he determined to be 365 days, 5 hours, 48 ​​minutes and 45 seconds. The difference to today's value of the tropical year is less than a second. He is therefore one of the most important astronomers.

Tycho Brahe had a decisive influence on the scientific ideal of later generations and founded the working style and methodology of modern science with his working method of more and more precise measurement and repeated checking. Although still partly at home in astrology and Christian dogmatics - but far less than his successor Kepler - his scientific approach was decades, if not centuries, ahead of his time.

His treasure trove of observations, laid down in the Rudolphinische Tafeln and later published by Kepler, was the basis not only for Kepler's theories, but also for Isaac Newton , who based his theory of gravitation on these observational values ​​almost a century later. Although Brahe was not yet familiar with binoculars , his readings were the most reliable for many decades after him.

As an irony of history, it seems that Brahe, who through his work inadvertently laid the foundation for the further expansion and completion of the heliocentric worldview, rejected it throughout his life. His own view of the world has only been preserved in the naming of the eccentricity in astronomy .


The deep Tycho crater in the center of the picture

The lunar crater Tycho and the crater Tycho Brahe on Mars were named in memory of Brahe, as was the asteroid (1677) Tycho Brahe , the Tycho Brahe Prize and the exoplanet Brahe .

On September 12, 2006, Tycho Brahe was erected a memorial across from the Wandsbek town hall to commemorate his eleven months in Hamburg-Wandsbek.

The ferry Tycho Brahe , named after Brahe, has been connecting Helsingborg in Sweden with Helsingør in Denmark since 1991 . The ferry was converted to battery-electric operation in 2018 .

In 1838, Carl Friedrich Philipp von Martius named a genus of palm Brahea Mart after Brahe .


  • De nova et nullius ævi memoria prius visa Stella . (German: Vom new and never before seen star), Copenhagen 1573, first book about the supernova from 1572 in the constellation Kassiopeia.
  • Editor Tycho Brahe: Diarium Astrologicum et Metheorologicum . (German: Astrological and Meteorological Diary), Uraniborg 1586, compiled by Brahe's student Elias Olsen Morsing,
  • De mundi aetheri recentioribus phaenomenis . (German: phenomena recently observed in the ethereal world), Uraniborg 1588.
  • Editor Tycho Brahe: En Elementisch oc Jordisch Astrologia . Uraniborg 1591, peasant rules about the weather, author were Brahe's printer.
  • Epistolarum Astronomicarum Liber Primus . (German: Correspondence on Astronomy - First Book), Uraniborg 1596 (First part of Brahe's correspondence, the second was published with Astronomiae Instauratae Progymnasmata ).
  • Astronomiae Instauratae Mechanica . (German: Die Neuere Astronomische Instrumentenlehre), Wandsbek 1598 (Reprint: KLP Koniasch Latin Press, Prague, 1996, ISBN 80-85917-23-8 ), colored original edition with handwritten dedication to be found in the digital collection of the LLB Detmold ), descriptions and pictures of buildings and instruments on Ven as well as autobiographical parts.
  • Stellarum octavi orbis inerrantium accurata restitutio . Wandsbek 1598.
  • Editor Johannes Kepler: Astronomiae Instauratae Progymnasmata . (German: Newer Introductory Exercises in Astronomy) Prague 1602–1603, second book about the Supernova from 1572, mostly completed on Uraniborg, original edition can be found in the Fondos Digitalizados of the Universidad de la Sevilla fondosdigitales.us.es .
  • De mundi aetherei recentioribus phaenomenis, liber secundus . (German: Phenomena recently observed in the ethereal world, second book), Frankfurt 1610,
  • Opera omnia sive astronomiae instauratae . Frankfurt 1648, in 15 volumes (Reprint: Olms, Hildesheim 2001, ISBN 3-487-11388-0 ), extensive planetary data collection Tycho Brahes.
  • About the New Star - A Song of Praise to the Heavenly Sciences . (Tübingen 2015, ISBN 978-3-89997-244-3 ), German first publication.


  • Fritz Krafft: Tycho Brahe. In: Exempla historica. Epochs of world history in biographies. Volume 27, Fischer Taschenbuch, Frankfurt am Main 1984, pp. 85–142.
  • Victor E. Thoren: The Lord of Uraniborg. A Biography of Tycho Brahe. Cambridge University Press, Cambridge 1990, ISBN 0-521-03307-1 .
  • John Louis Emil Dreyer: Tycho Brahe. A picture of scientific life and work in the sixteenth century. Edinburgh 1890 (digitized) ; German edition: Tycho Brahe. A picture of scientific life and work in the sixteenth century. Braun, Karlsruhe 1894 ( digitized version ); Reprint: Sänd Reprint, Vaduz 1988.
  • John Robert Christianson: On Tycho's Island. Cambridge University Press, Cambridge 2000 ( limited preview in Google Book search).
Scientific treatises
  • John Robert Christianson, Alena Hadravová, Petr Hadrava, Martin Šolc (eds.): Tycho Brahe and Prague. Crossroads of European science. Harri Deutsch, Frankfurt am Main 2002, ISBN 3-8171-1687-X .
  • Owen Gingerich, Robert S. Westman: The Wittich Connection. Conflict and Priority in Late Sixteenth-Century Cosmology. American Philosophical Society, Philadelphia 1988 ( limited preview in Google Book search).
  • Michael Weichenhan: "Ergo perit coelum ...". The supernova of 1572 and the overcoming of Aristotelian cosmology. Stuttgart 2004, ISBN 3-515-08374-X .
Historical novels and short stories
  • Alexandra Coelho Ahndoril: The King's Astronomer. List, Berlin 2004, ISBN 3-548-60460-9 .
  • Max Brod : Tycho Brahe's way to God. A novel. With an afterword by Stefan Zweig . Suhrkamp, ​​Frankfurt am Main 1984, ISBN 3-518-36990-3 .
  • Joshua Gilder: The Kepler Case. Murder in the name of science. List at Ullstein, Berlin 2005, ISBN 3-548-60638-5 .
  • Alfred Otto Schwede: I was the junker's fool. A story about the astronomer Tycho Brahe. Union, Berlin 1983.
  • Mattias Gerwald: The dying sun. Bastei Lübbe, Bergisch Gladbach 2004, ISBN 3-404-15127-5 .

Web links

Commons : Tycho Brahe  - album with pictures, videos and audio files
Wikisource: Tycho Brahe  - Sources and full texts

Overview Pages:

Original works as online edition of the Saxon State Library - Dresden State and University Library:

Scientific secondary sources:

Individual evidence

  1. ^ Ancestors of the Tycho Brahe - Skeel & Kannegaard Genealogy
  2. See the entry of Tycho Brahe's matriculation in the Rostock matriculation portal
  3. ^ "Mathematics Genealogy Project" Mathematics Genealogy Project (in English)
  4. ^ Johann Bernhard Krey: In memory of the Rostock scholars from the last three centuries. Rostock, 1816. p. 20
  5. Per Sörbom: Tycho Brahe - A Passionate Astronomer. 6th edition. The Saab-Scania Griffin, 1992.
  6. ^ Descendants of Tycho Brahe - Tycho gifte sig med en ofrälse kvinna
  7. ^ Tycho Brahe , accessed May 20, 2015.
  8. Tycho Brahe. In: John Lankford (ed.): History of Astronomy: An Encyclopedia. Routledge, 1997, p. 99. (books.google.de)
  9. David Brewster: The martyrs of science; or, The lives of Galileo, Tycho Brahe, and Kepler. New York 1841, p. 125.
  10. ^ John Robert Christianson: On Tycho's Island. P. 100.
  11. Walther Gerlach: Johannes Kepler The ethicist of natural research. In: The natural sciences. 48, 1961, pp. 85-96, doi : 10.1007 / BF00636034 . P. 90 above.
  12. Sternenburg - an astronomical observatory under the earth's surface, description of the Tycho Brahe Museum on Ven ( Memento from February 23, 2014 in the Internet Archive )
  13. ^ John Louis Emil Dreyer: Tycho Brahe. A picture of scientific life and work in the sixteenth century Edinburgh 1890, p. 105.
  14. a b Researchers dig up Tycho Brahe's bones again. Spiegel Online, November 15, 2010, accessed November 16, 2010 .
  15. Joshua and Anne-Lee Gilder: The Kepler Case. Murder in the name of science . List-Verlag, Berlin 2005.
  16. ^ Statement by the Kepler Society on the book by Joshua Gilder and Anne-Lee Gilder. March 4, 2005, archived from the original on November 25, 2015 ; Retrieved November 26, 2015 .
  17. ^ Mercury poisoning ruled out as cause of Tycho Brahe's death. Aarhus University, November 14, 2012, accessed April 9, 2018.
  18. Walther Gerlach : Johannes Kepler - Der Ethiker der Naturforschung , Munich 1960.
  19. Jürgen Hamel: History of Astronomy in Source Texts . Spektrum Akad. Verlag, Heidelberg 1996, ISBN 3-8274-0072-4 , pp. 37 .
  20. Brahe (Tycho). In: Johann Heinrich Zedler : Large complete universal lexicon of all sciences and arts . Volume 4, Leipzig 1733, column 989-991.
  21. Pierre Gassendi : Tychonis Brahei, equitis Dani, Astronomorum Coryphaei, vitae Accessit Nicolai Copernici, Georgii Peurbachii, & Joannis Regiomontani, Astronomorum celebrium, Vita . Hagae Comitum (The Hague), Vlacq (1655) GoogleBooks
  22. ^ Owen Gingerich, Robert S. Westman: The Wittich Connection: Conflict and Priority in Late Sixteenth-Century Cosmology. American Philosophical Society , 1988, GoogleBooks
  23. Tycho Brahe: Astronomiae Instauratae Progymnasmata. P. 51.
    JST Gehler: Physical dictionary.
  24. 2006: Tycho Brahe - Monument at the Wandsbeker town hall
  25. Hållbarhet | Startsida. Retrieved January 2, 2019 .
  26. Lotte Burkhardt: Directory of eponymous plant names . Extended Edition. Botanic Garden and Botanical Museum Berlin, Free University Berlin Berlin 2018. [1]