Tycho Brahe

Tycho Brahe (born Tyge Ottesen Brahe) (December 14, 1546 – October 24 1601) was a Danish nobleman known primarily for his work as an astronomer and an astrologer (the two were highly related in his day), as well as an alchemist. He 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. 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 Tychonian system. His best known assistant was Johannes Kepler, who would later use Tycho's astronomical information to develop his own theories of astronomy.

Tycho and astronomy

Tycho was the preeminent observational astronomer of the pre-telescopic period, and his observations of stellar and planetary positions achieved unparalleled accuracy for their time. For example, Tycho measured Earth's axial tilt as 23 degrees and 31.5 minutes, which he claimed to be more acurate than Copernicus by 3.5 minutes. After his death, his records of the motion of the planet Mars enabled Kepler to discover the laws of planetary motion, which provided powerful support for the Copernican heliocentric theory of the solar system.

Related Topics:
Stellar - Planet - Axial tilt - Mars - Laws of planetary motion - Copernican - Heliocentric theory

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Tycho himself was not a Copernican, but proposed a system in which the planets other than Earth orbited the Sun while the Sun orbited the Earth. 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.

Related Topics:
Earth - Sun - 1616

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He was aware that a star observed near the horizon appears with a greater altitude than the real one, due to atmospheric refraction, and he worked out tables for the correction of this source of error.

Related Topics:
Altitude - Refraction

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To perform the huge number of products 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.

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