The Life of Tycho Brahe

The Greatest Astronomer of the 16the Century

Born in 1546, Tycho Brahe was one of the most noted astronomers of the 16th Century and a leading figure of the scientific revolution.

Tycho Brahe was born on December 14, 1546 at his family’s ancestral home of Knudstrup Castle, in Denmark. Tycho’s father, Otte Brahe was a high ranking noble in the court of the King of Denmark. Tycho’s mother, Beate Bille also came from a powerful family that had produced many important church officials and politicians.

Tycho’s Childhood

When Tycho was two, he was sent to live with his uncle, Jorgen Brahe, who was also a member of the Danish court. Tycho is known to have gone to school until the age of 12, at which point he went to the University of Copenhagen. While at university, Tycho primarily studied law, but he also took a number of other subjects including astronomy. He was impressed by the fact that a solar eclipse that occurred on August 21, 1560 had been predicted. As a result, he began to make his own astronomical observations with the assistance of his professors.

In 1565, Tycho’s uncle, Jorgen Brahe died after contracting pneumonia. He fell ill after he saved the King of Denmark from drowning. In April, 1567, Tycho returned home to his father, where he set up a law practice. When he was not working, Tycho made regular trips to Rostock, Augsburg, Frieburg and Basel, furthering his interest in astronomy. Following the death of his father in 1571, Tycho began to construct an observatory and alchemical laboratory at Herraved Abbey.

Supernova SN 1572

In 1572, a new star appeared unexpectedly in the constellation Cassiopie. Since ancient times, celestial immutability had been a major tenet of Geocentrism. As a result most astronomers believed that the object was located between the Earth and the moon. However, based on the lack of stellar parallax, Tycho believed that the object was much farther away, which suggested that it was not a planet, but a new star. Over the next several months, Tycho observed the object and published his findings later that year in a book a called De Nova Stella. The phenomenon Tycho observed is now known to be a supernova remnant catalogued as supernova SN 1572. In the prologue of his book, Tycho was critical of those who had dismissed the implications of his discovery.

Following the publication of his book, Tycho left Denmark in 1575 to travel abroad. While traveling, Tycho visited with Wilhelm IV, the Landgrave of Hesse-Kassel, to see his observatory. Following this, Tycho visited Frankfurt, Vienna, and Basel, where he planned to relocate. However, not wanting to lose one of Denmark’s most prominent scientists, the King of Denmark offered him Hven Island off the Danish coast and funding for an observatory and a basement laboratory for his studies in alchemy.

Tycho aspired to achieve new levels in accuracy, sometimes charting the stars and planets to within 1.5 degrees of their actual position in the sky. After his death, his record of the orbit of Mars provided critical supporting evidence for Kepler’s Laws of Planetary Motion.

The Tychonic Model

Tycho’s research led him to reject the ancient geocentric understanding of the universe. At the same time, he was not a supporter of Copernicus. This led him to develop what eventually become known as the Tychonic model of the solar system, in which the planets orbit the sun, and the sun orbits the Earth. This provided a safe position for astronomers who were dissatisfied with the Geocentric model of the solar system, but were wary of religious persecution. The Tychonic model also offered an important innovation over Geocentrism and Copernican astronomy. Geocentric astronomers, along with Nicolaus Copernicus, believed that the planets were carried through their orbits by a series of crystalline spheres, where as the Tychonic model did not.

Tycho believed that the Earth was at the centre of the solar system, on the basis that he felt that Earth moved too slowly to be in orbit around the sun. He also argued that if the Earth was moving, it should be possible to observe a shift in the positions of the stars and planets in the night sky over a period of several months. This phenomenon, known as stellar parallax, was not positively identified until the late 1830s.

Tycho’s Legacy

Although, his model of the solar system was quickly discredited, Tycho’s observations remained an important contribution to the Scientific Revolution. Tycho is considered to be one of the early empirical scientists and set standards for accuracy and precision in the collection of astronomical data. His contributions to astronomy are considered to be such that craters on the Moon and Mars bear his name.

In 1601, Tycho contracted a bladder ailment while staying in Prague, in the Czech Republic. He died on October 24, 1601, however, there is circumstantial evidence suggesting that he died of mercury poisoning. Tycho Brahe is buried in the Church of Our Lady before Tyn, near the Prague Astronomical Clock.


Hoskin, M. (ed.) The Cambridge Concise History of Astronomy CUP 1999

Pannekoek, A. A History of Astronomy Allen & Unwin 1961

Linton, Christopher M. (2004). From Eudoxus to Einstein—A History of Mathematical Astronomy. Cambridge: Cambridge University Press.


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