Tübingen observatory

Tübingen Observatory (June 2018)

Today's Volkssternwarte Tübingen is an observatory maintained by the city of Tübingen , which used to be an important research institute of the Eberhard Karls University of Tübingen . It is located on the Waldhäuser Höhe next to the building of today's technology park Tübingen-Reutlingen .

history

Tübingen's history of astronomy and the observatory goes back a long way. Former scientists and observatories made significant research contributions, including in optics and instrument construction , in time determination and photometry .

Restaurant entrance

Tübingen observatory with biotechnology park

In 1507 the learned pastor and instrument maker Johannes Stöffler was appointed by Duke Ulrich von Württemberg as the first astronomy teacher at the State University of Tübingen . Stöffler became well known for his astronomically calculated calendars and tables, clocks and celestial globes, which u. a. were used by Nicolaus Copernicus . In 1511 Stöffler built an astronomical clock for the Tübingen town hall.

In the following years, well-known scholars in the field of astronomy worked in Tübingen, including Philipp Imsser from Strasbourg, Philipp Apian from Ingolstadt, Samuel Eisenmenger (called Siderocrates ) from Bretten and Michael Mästlin from Göppingen. With Mästlin's support, the first work “Mysterium Cosmographicum” by his pupil Johannes Kepler was printed in Tübingen in 1596 . The attic of the Tübingen collegiate church serves Maestlin as a kind of pinhole camera - the light from the sun and moon fell through small holes in the roof tiles and was shown enlarged. In 1631 Wilhelm Schickard , polymath, inventor and builder of the first calculating machine , was appointed professor of astronomy.

In 1752 a university observatory was set up on the north-east tower of Tübingen Castle, but the telescope pillar was not adequately funded . The first director was Georg Wolfgang Krafft , who previously taught in Saint Petersburg . The observatory had a quadrant made by the Parisian manufacturer Langlois, a pendulum clock and a 16- foot (approx. 5 m) long lens telescope . At the time, the Tübingen observatory boasted as one of the best in Germany. When Johann Kies , who had worked at the Berlin observatory until then , took over the professorship, however, he judged the furnishings and the buildings to be bad and inadequate and requested a new building.

Under his successor, Christoph Friedrich Pfleiderer , the observatory was renewed and improved in 1785. From 1795 the theologian Johann Gottlieb Bohnenberger worked successfully as an observer at the observatory, later he took over the chair of mathematics and physics . He wrote important textbooks and designed numerous devices. In the palace garden he had an observation dome built with a rotating roof. In 1816 he founded the first specialist astronomical journal together with the Gotha astronomer Lindenau. In addition, he carried out the scientific survey of Württemberg , whereby the observatory was the zero point.

In 1833 Johann Gottlieb Nörrenberg took over the professorship for mathematics, physics and astronomy. a. with the development and improvement of optical devices. During this time, the observatory was rebuilt and a refractor with 15 cm aperture and 2.5 m focal length was purchased from Joseph von Fraunhofer’s workshop . In 1852 Julius Zech became professor of mathematics and director of the observatory. He mainly deals with theoretical celestial mechanics . From 1865 to 1888 the observatory was used almost exclusively for demonstration purposes as part of the lecture on astronomy.

From 1912 the physicist Hans Rosenberg was head of the now outdated observatory. He set up a private observatory on his house on Österberg , which consisted of a 4.3 m observation dome and was equipped with an apochromat with a 13 cm aperture and 2.4 m focal length. Rosenberg determined the moon's albedo there and developed new methods for measuring star brightness . In 1926 he went to Kiel, but was forced to emigrate during the Third Reich . In 1925 he sold the dome and its furnishings to the University of Kiel, where he worked from 1926. He sold the refractor, the Riefler clock and some smaller instruments to the University of Tübingen for the Kepler observatory, which was also planned on the Österberg. His observatory was later demolished, the whereabouts of the instruments is unclear - they may still be in the possession of the University of Tübingen.

On the occasion of the 400th anniversary of Johannes Kepler's death, the construction of a new observatory was planned in 1930, whereby a piece of land on the Österberg was acquired and donations were collected. Due to the global economic crisis , however, the project was never carried out.

After the National Socialists came to power , the Tübingen physicist Hans Bethe was forced to emigrate to the USA in 1933 because of his Jewish descent . There he developed the theory of nuclear fusion inside stars , for which he later received the Nobel Prize . In 1934 a chair for astronomy was set up in Tübingen, but not filled.

In 1949 Heinrich Siedentopf , who came from Jena , took over the chair and set up astrophysical research. In 1956 a new observatory was put into operation on the Waldhäuser Höhe. The main instrument was a 30 cm refractor with a 5 m focal length, which had been designed by the Carl Zeiss company as early as 1924 . Under the direction of Siedentopf's successor, Joachim Trümper, Tübingen took part in important projects in X-ray astronomy in 1971 .

In 1972 the Astronomical Association Tübingen e. V. founded - largely thanks to the astrophysicist Kurt Walter . The aim was to organize public observations of the sky at the observatory and to promote general astronomical education.

Under Michael Grewing, director of the astronomical institute from 1977, research in the field of the ultraviolet spectral range was expanded. Since then, the Tübingen scientists have been involved in projects such as ORFEUS , MIR-HEXE and Hipparcos .

In 2003, the astronomical institute gave up the observatory because a research observatory was being built elsewhere. The observatory was acquired by the city of Tübingen. Today it is part of the Technology Park Tübingen-Reutlingen .

The Astronomical Association of Tübingen regularly offers public sky observation and astronomical lectures at the observatory.

Instruments

The main instrument is still the 30 cm refractor ( achromat ) with a focal length of 5 m. The instrument was commissioned in 1924 by the privy councilor and Nobel laureate Carl Bosch at a price of 63,440 gold marks from the Jena company Carl Zeiss. The device was delivered in 1925 and was in Bosch's private observatory in Heidelberg . It was ceremoniously handed over to Tübingen in the early 1950s. Since 1973 it has been used by the Tübingen Astronomical Association for public tours.

Others

The building was converted in 2004 on behalf of the city of Tübingen by the Tübingen architects Häfele – Architekten BdA, so that a large part of the space can be used as a restaurant . However, the “Sternwarte” restaurant closed in autumn 2016. A new tenant reopened the restaurant under the name "Quartier an der Sternwarte" in 2017 with a different concept.

A footpath runs through a small park that was laid out in 2009, past the biotechnology center. The planetary orbits are marked in relation to each other along this path. In addition, a "living analemmatic sundial " is located in the park, embedded in the ground . If you stand at the correct and marked point for the season, the time can be read from the shadow cast by the body (both in CET and WOZ ).