Tycho Brahe Biography and Contributions to Science

Robert Johnston

Tycho brahe (1546-1601) was a Danish astronomer, astronomer, and alchemist known for his accurate observations of celestial bodies, which changed beliefs about how the universe was organized. 

Although Brahe's observations showed that the system of the time was flawed, he did not favor Nicolas Copernicus and his heliocentric model. Their model proposed that the moon and the sun revolved in orbits around the Earth, while the other five known planets revolved around the sun..

His observations included a study of the solar system and the position of more than 700 stars, being five times more exact than others of the time. In fact, he was described as "the first competent mind in modern astronomy to have a burning passion for exact empirical facts.".

Article index

  • 1 Biography
    • 1.1 Family
    • 1.2 Studies
    • 1.3 Death of the uncle
    • 1.4 Astronomical training
    • 1.5 Back to astronomy
    • 1.6 Family life
    • 1.7 Stay in Copenhagen
    • 1.8 Island of Hven
    • 1.9 Intervention of Rodolfo II
    • 1.10 Death
  • 2 Tycho Brahe's Model of the Universe
  • 3 Contributions to science
    • 3.1 Supernova observation
    • 3.2 Uraniborg or Castle of Heaven
    • 3.3 Astronomical measuring instruments
    • 3.4 1000 stars
    • 3.5 Refraction of light
  • 4 Kepler, Brahe's successor
    • 4.1 Rudolfin tables
  • 5 References


Tycho Brahe was born on December 14, 1546 in the province of Skåne, specifically in the castle of Knutstorp. This region was part of Denmark at the time it was born, currently it makes up the nation of Sweden.

Tycho was initially christened Tyge. However, later in his life he decided to change it to the Latinized form: Tycho.


Tycho the eldest son of the marriage of Otte Brahe and Beate Bille, a noble family.

Otte Brahe had been an advisor to the king and the last position he held was that of governor of Helsingborg Castle. For her part, Beate Bille was part of a family group from which several politicians and priests of great relevance to society had emerged..

When Tycho was barely a year old, he was taken by his uncle Joergen Brahe to Trostup Castle, where he lived. It was Joergen who took it upon himself to raise him; since he had no children, he was able to fulfill this task with great dedication.

Since he was little, Tycho obtained a very careful training in Latin, because his uncle planned that he would dedicate his life to serving the king, for which he was preparing him in the areas that were necessary to fulfill that task..


When Tycho turned thirteen, in 1559, he entered the University of Copenhagen. In this house of studies he was trained in topics related to astronomy and mathematics.

It is said that his interest in these sciences was born precisely while in Copenhagen, when a solar eclipse took place. This happened on August 21, 1560 and what really impressed him was the fact that the eclipse was predicted in advance..

Two years after this episode, Tycho entered the University of Leipzig, in Germany, where he was supposed to study law. However, he sought to devote most of his time to the field of astronomy, with which he was fascinated.

Tycho was in Leipzig for three years, and in 1565 he returned to Copenhagen, motivated by the fact that Denmark and Sweden were at war and the context had become somewhat complicated.

Uncle death

On June 21, 1565, Joergen Brahe, Tycho's uncle, died. The reason for his death was that he had been in poor health after having to save King Frederick II, who had fallen into the water from the bridge of a castle.

Joergen left a great inheritance to Tycho, who used it to continue his studies in astronomy, since his family did not support him in it.

Astronomical training

From this moment on, Tycho Brahe devoted himself fully to astronomy. First, he traveled to the University of Wittenberg, located in Germany.

Then he entered the University of Rostock, the oldest in northern Europe, where he studied alchemy, astrology and medicine..

It can be said that from 1567 Tycho's career took off and he became a more popular character.

During this period he visited Wittenberg, Basel (Switzerland) and Augsburg (Germany). In this last city he settled, at the beginning of the year 1569, and devoted himself to astronomical observation..

His father Otte Brahe became seriously ill in 1570, causing Tycho to travel again to Denmark to attend to him. A year later, in May 1571, his father died.

Back to astronomy

For the remainder of that year Tycho ignored astronomy and momentarily devoted himself more to chemistry..

However, at that time another astronomical event occurred that made him focus again on this science: a new star appeared in the constellation of Cassiopeia, which could be seen for a period of 18 months..

Tycho carefully recorded all his observations and later published them in his work. By nova stella.

Family life

Tycho Brahe lived with a young woman named Kirstine, a native of the vicinity of Knudstrup Castle. The couple did not formalize their union, but together they had eight children.

Of these eight descendants, only 6 survived, two boys and four girls. After Tycho's death, they were recognized as his legitimate children.

Stay in Copenhagen

Tycho's life passed quietly in Copenhagen, but he was not entirely comfortable with his work reality there, so much so that he considered the possibility of moving to another city.

The king was aware of the growing importance that Tycho was acquiring, so he tried to persuade him to stay in Copenhagen. In the middle of the negotiations, the king finally gave Tycho the island of Hven.

Tycho accepted the proposal and went to live there, where he also built a large observatory that was later called Uraniborg..

Island of hven

Brahe remained on the island of Hven between 1576 and 1597. This space was gradually being conditioned, so that he had everything he needed for his observations.

Another observatory was built, in addition to a printing press and a paper factory, a well-equipped library and comfortable offices for him and his assistants..

The main task that Brahe carried out in his laboratory was to measure the positions of the different planets taking as reference the immobile stars. His observations became so relevant that they were the ones that were considered true..

In 1588 King Frederick II died and his son, Cristián IV, ascended to the throne. From this moment on, Tycho's popularity declined a bit..

In 1596, when Cristián IV was officially named king, he removed Tycho's properties outside the continent and also cut the budget allocated to observatories. In view of this context, Tycho decided to leave this island and head towards Rostock.

Rodolfo II's intervention

Brahe was still looking for an ideal place to place his observatory without success, when he received a communication from the Emperor Rudolph II of Habsburg, who was based in Prague and who was always characterized by giving importance to the scientific field.

In 1599 Tycho traveled to Prague and Rudolph II received him. The emperor's offer was to appoint him as an imperial mathematician, grant him an income and give him a choice between three castles to choose the ideal one for his observatory..

In this way Brahe was able to continue his observations and studies. He was around fifty years old, and he worked in this space during the next few years of his life. It was there that he maintained a close relationship with the scientist Johannes Kepler, who was his assistant.


On October 13, 1601, Tycho Brahe presented a severe picture of health. At first it was believed that the cause that triggered the discomfort was that he suffered from uremia.

Long after Brahe's death in 1999, studies were done on his hair and large amounts of mercury were found, used by this scientist in several of his experiments. It is currently believed that the cause of death was poisoning caused by mercury.

He was delirious for several days, but showed considerable improvement on October 24. After giving instructions on his assets and pending work, Tycho Brahe died that October 24, 1601.

A large number of people participated in the burial ceremony and her body lies in Prague, in the Church of Our Lady of Tyn.

Tycho Brahe's model of the universe

To explain Tycho Brahe's model of the universe, we must first understand the ideas of his predecessors on this topic..

Claudius Ptolemy (90/100 AD - 170 AD), in his astronomical treatise Almagest, presented a model of the geocentric universe in which the Earth was the center of the universe and remained motionless, while the sun, moon, planets and stars revolved around it.

On the other hand, the Polish astronomer of the Renaissance, Nicholas Copernicus (1473-1543), formulated the heliocentric theory of the solar system. This heliocentric model proposes that the sun is the center of the universe and that orbiting around it are the moon, the Earth, Mercury, Venus, Mars, Jupiter and Saturn..

Brahe proposed a model of the intermediate universe between the geocentric model of Ptolemy and the heliocentric universe of Copernicus.

In this new model of the universe, the sun and the moon revolve around the immobile Earth, while Mercury, Venus, Mars, Jupiter and Saturn revolve around the sun..

We currently know that this theory does not correspond to reality, since our solar system consists of a center (sun) and 8 planets (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune) that revolve around the sun..

We also know that our solar system has other astronomical objects, satellites, minor planets, among others. Furthermore, so far, more than 500 solar systems have been found in our galaxy and new systems are discovered every year. However, it is estimated that there could be more than 100 trillion in the Milky Way alone..

Contributions to science

Supernova observation

Since ancient times, based on the axiom of celestial immutability on the Aristotelian worldview, it had been held that the world behind the orbit of the moon was eternally immutable..

However, on November 11, 1572, Tycho Brahe was able to observe a supernova, today known as SN1572 or Nova Tycho, called by him in his time Stella Nova. These observations were summarized in his work By nova stella. Two years later, in 1574, the supernova could no longer be observed.

During the eighteen months that the new star was visible, Brahe made strict observations and measurements that told him that there was no daily parallax between the astro and the background of fixed stars..

This implied that the Stella Nova was beyond the moon and the Earth's orbit, thus contradicting the belief of the immutability of the celestial bodies..

Uraniborg or Castle of Heaven

The Emperor Frederick II gave Brahe the Isle of Hven, and a large amount of money annually, enough to carry out the construction of Uraniborg. This was the last primitive astronomical observatory before the invention of the telescope in 1608, being the first modern observatory one hundred percent financed by the government..

Uraniborg Palace

Uraniborg Palace gets its name from Urania, muse of astronomy. This is where Tycho Brahe made most of his observations and where he built new large astronomical instruments..

Astronomical measuring instruments

Since the solar eclipse of 1560, Tycho insatiably sought precision in his observations, as well as excellence in their records..

To carry out this task, it was necessary for him to apply and improve various astronomical measuring instruments. Here are some of the devices with which Brahe observed the skies night after night:

From left to right: Quadrant, Armillary Sphere and Sextant

1000 stars

All his instrument design allowed him to measure the position of stars and planets with a precision far superior to that of his time. In this way, he developed a stellar catalog of more than 1000 fixed stars..

Refraction of light

The refraction of light was first perceived by Tycho Brahe. He corrected the astronomical measures of this effect and also produced a complete table of it..

Kepler, Brahe's successor

We cannot speak of Tycho Brahe without naming his successor: Johannes Kepler (1571-1630), German astronomer and mathematician, and one of the most important scientists in history.. 

There is evidence that the relationship between astronomers was not the most cordial. Apparently, Tycho refused to teach Kepler the full set of observations of the trajectory of the planets, their records and astronomical observations..

Until Brahe's death, Kepler did not gain access to all his informational baggage, which allowed him to continue investigating, so that several years later he could come to enunciate his three laws on the movement of the planets.

Rudolfin tables

Some time before his death, Tycho Brahe, entrusted Kepler with the task of finishing the Rudolphine tablets, named in this way with the intention of paying homage to Emperor Rudolph II..

Brahe developed them to compile some new star leaderboards. He gave Kepler all his astronomical data with the responsibility of demonstrating the validity of his model of the universe against that of Nicolás Copernicus..

The publication of this stellar catalog was carried out by Johannes Kepler in the year 1627.


  1. John Robert Christianson; On Tycho's Island: Tycho Brahe and His Assistants, 1570-1601.
  2. Encyclopædia Britannica; (7-20-1998); Uraniborg. Recovered from britannica.com.
  3. R. Taton, C. Wilson, Michael Hoskin; (2003); Planetary Astronomy from the Renaissance to the Rise of Astrophysics, Part A.
  4. Astronomiae Instauratae Mechanica, Smithsonian Institution. Recovered from sil.si.edu.
  5. Dreyer, Tycho Brahe: A Picture of Scientific Life and Work in the Sixteenth Century, Edinburgh 1890. Reprinted New York 1963. Recovered from sites.hps.cam.ac.uk.
  6. Chapman, "Tycho Brahe in China: The Jesuit Mission to Peking and the Iconography of the European Instrument-Making Process", Annals of Science 41 (1984), pp. 417-433. Recovered from sites.hps.cam.ac.uk.
  7. Victor E. Thoren; The Lord of Uraniborg: A Biography of Tycho Brahe.

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