Tycho Brahe Presentation PDF

“Rock of Star” of Astronomy TYCHO BRAHE  HISTORY  Tycho Brahe He was born in (Tyge Ottesen Brahe, 14 December 1546 – 24 October 1601), generally called Tycho for short, was a Danish astronomer of the Renaissance, known for his comprehensive and unprecedentedly accurate a...

“Rock of Star” of Astronomy TYCHO BRAHE  HISTORY  Tycho Brahe He was born in (Tyge Ottesen Brahe, 14 December 1546 – 24 October 1601), generally called Tycho for short, was a Danish astronomer of the Renaissance, known for his comprehensive and unprecedentedly accurate astronomical observations. He was known during his lifetime as an astronomer, astrologer, and alchemist. He was the last major astronomer before the invention of the telescope. Tycho Brahe has also been described as the greatest pre-telescopic astronomer.  TYCHO BRAHE’S OBSERVATION  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. Tycho was not a Copernican, but proposed a "geo-heliocentric" system in which the Sun and Moon orbited the Earth, while the other planets orbited the Sun. Although Tycho's planetary model was soon discredited, his astronomical observations were an essential contribution to the scientific revolution.  1572 NOVAE (super)nova.Shown is a diagram in Tycho Brahe's 1573 book, "De Nova Stella", showing the position of the 1572 (super) nova with respect to the bright stars in the constellation Cassiopea. A lack of detectable parallax forced Brahe to locate the nova beyond the sphere of the Moon, i.e., in the celestial realm, supposedly unalterable according to Aristotelian doctrine.  1577 Comet and Orbital ReconstructionThe comet Shown here is a depiction of the 1577 comet observed by Tycho, which remained visible from November 1577 to January 1578. His observations revealed no measurable parallax, implying that the comet was located beyond the sphere of the moon. His reconstruction of the comet's orbital path, from brightening and dimming and displacement with respect to the background stars, indicated that the comet moved across the concentric planetary crystalline spheres. This supported the notion of a "fluid heaven" and contradicted the physical reality of these spheres as real, hard, transparent, and contiguous spherical shells.  TYCHONIAN PLANETARY MODEL  The Tychonian planetary model, conceived by Tycho around 1583, was an unconvincing attempt to reintroduce geocentrism in the "Copernican planetary system." From his observations of the 1572 (super)nova and 1577 comet, Tycho was convinced of the falsity of the Ptolemaic system. In Tycho's system the Earth is absolutely fixed, so that the daily motion of the fixed stars is ascribed to a daily rotation of the outermost sphere, as in the Ptolemaic system. A similar planetary system was proposed in antiquity by Heraklides of Pontus (ca. 388–310 BC)who, however, ascribed to the Earth a daily axial rotation.  TYCHO’S INSTRUMENTS  Revolving Wooden Quadrant: Tycho's revolving wooden quadrant, 1.6 meter in radius, was built in 1586. It had an estimated accuracy of 32.3 seconds of arc, based on eight reference stars.  TYCHO’S INSTRUMENTS  BRASS AZIMUTHAL QUADRANT: Tycho's brass azimuthal quadrant, 65 centimeters in radius, was built in 1576 or 1577. It was one of the first instruments built at Hveen, and was used for observations of the 1577 comet. It had a estimated accuracy of 48.8 seconds of arc.  TYCHO’S INSTRUMENTS  GREAT GLOBE: Tycho's great globe, about 1.6 meter in radius, was over 10 years in the making. This instrument came in service in late 1580. Most of the work involved making the hollow wooden globe as perfectly spherical as possible, after which it was covered in brass plates.The globe had two primary scientific uses; it came to be used to record the position of stars observed by Tycho. By 1595 he had 1000 accurately observed stars inscribed on the globe. However, it was originally intended as a computational device. By means of auxiliary circles, the local azimuth/altitude coordinates, as measured with Tycho's instruments, were converted into the conventional celestial coordinates used to record stellar and planetary positions.  TYCHO’S INSTRUMENTS  ARMILLARY SPHERE: An "armillary sphere" is a model of objects in the sky (in the celestial sphere), consisting of a spherical framework of rings, centered on Earth, that represent lines of celestial longitude and latitude and other astronomically important features such as the ecliptic. As such, it differs from a celestial globe, which is a smooth sphere whose principal purpose is to map the constellations. Tycho's armillary sphere was 1.6 meter in radius and built in 1581. Tycho rapidly gave up on using large versions of the classical armillary sphere, as he found their accuracy compromised by flexing and bending due to the great weight of the various components. This lead to the design of the vastly superior equatorial armillaries.  TYCHO’S INSTRUMENTS  TRIANGULAR SEXTANT: Tycho's triangular Sextant, about 1.6 meter in radius, was built in 1582. As Tycho's sextants grew in size, they became fixed instruments, although Tycho's ingenious globe mount retained a lot of the versatility of use of smaller, conventional portable sextants.  TYCHO’S INSTRUMENTS  Great Equatorial Armillary: Large instruments such as these, with improved sighting devices and measuring scales, as well as Tycho's advanced procedures to correct for atmospheric refraction, allowed him to compute stellar and planetary positions consistently accurate to within a minute of arc. Tycho's determination of the tropical year was too small by about one second, and his determination of the Earth's orbital tilt (which Tycho, committed to the Earth's fixity as he was, referred to as the angle between the ecliptic and the celestial equator) by half a minute of arc. Tycho's great equatorial armillary, 3 meters in diameter, was built in 1585. This is an armillary sphere reduced to its bare essentials, and one of Tycho's workhorse instruments. It has an estimated accuracy of 38.6 seconds of arc.  TYCHO’S INSTRUMENTS  Revolving Steel Quadrant: An improvement over Tycho's wooden version, his revolving steel quadrant, 2 meters in radius, was built in 1588. It's estimated accuracy was 36.3 seconds of arc. THANK YOU!!