Urania observatory Zurich

The observatory and the Urania office building (2006)

The Urania observatory Zurich (official name) is a public observatory in the Lindenhof district ( District 1 ) of the Swiss city of Zurich . It owes its name Urania to the muse of astronomy from Greek mythology - derived from Uranos , the heaven in the form of a god.

investment

building

The origins of the public observatory go back to a first observatory on the roof of the Zunfthaus zur Meisen . From this location the “Astronomical Commission” succeeded for the first time in 1759 in calculating the culminatio solis and thus the exact location of the city of Zurich on the globe. In later years astronomical observations were made from the (southern) "Karlsturm" of the Grossmünster . The Federal Observatory was built by Gottfried Semper for research purposes between 1861 and 1864 in connection with the construction of the Federal Institute of Technology (ETH) , but was usually not open to the public.

The newly built Uraniastrasse towards the Limmat, viewed from the approximate location of the observatory (1908)

The sale of a plot of land at Werdmühleplatz to the merchant Abraham Weill-Einstein, with the reservation that “ within five years of the transfer of ownership, a beautiful building appropriate to the location of the building site would be built ” initiated the planning of the oldest public observatory in Switzerland. In April 1905, the building section submitted the project draft to the city council, and construction began in mid-June 1905 as part of the “Urania axis” planned by Gustav Gull, Sihlporte – Uraniastrasse – Zähringerplatz. This was a project with development plans for a "Greater Zurich", of which only parts of the "Urania Office City" with the residential and commercial building and the observatory (Uraniastrasse 9) and the administrative buildings I-IV for the purpose of combining the municipal offices on the left-hand side of the Limmat .

The Urania observatory was the first concrete building to be erected in Zurich. The 51 meter high tower was built without connection to the rest of the house. It stood on a foundation of 48 wooden piles that were rammed 12 meters into the sea chalk construction site until they hit rock. Above it was a cast and vibration-free concrete slab that supported the base of the telescope. On Saturday, June 15, 1907, the office building and the public observatory opened. Since then, the 51 meter high tower has been one of the most striking buildings at the western end of the historic old town and has been a listed building since 1989 .

telescope

The telescope is provided with a color-correcting, Fraunhofer two-lens system 30 centimeters aperture and a focal length equipped of 5.05 meters. It allows up to 600-fold magnification of the observed celestial objects . Mostly 150 to 205 times magnifications are used. The telescope in the dome forms the center of the imposing tower: the device stands on a pillar that extends through the entire building without contact and into the foundations of the Urania commercial building. The dome structure is supported against vibrations from inside and outside with anti-vibration supports.

In contrast to smaller, publicly accessible public observatories, the Zurich Urania held a special position at the beginning of the 20th century. The twelve-ton optical telescope was developed by the Carl Zeiss company in Jena , the leading manufacturer of optical instruments at the time. The telescope was considered a technical masterpiece, as a contemporary source reports: “ This instrument represents the most perfect thing that can be manufactured according to the current state of science, precision mechanics and optics. Especially with regard to its particular construction and with regard to the popular purposes it has to serve, there is nothing like it ». The telescope shaped the history of technology as the “Urania type”; a model was in the Deutsches Museum .

On the occasion of the hundredth anniversary, the telescope and the dome were to be comprehensively renewed. The now one hundred year old Zeiss telescope, which continues to meet today's requirements with its imaging performance, was dismantled in March 2006 and extensively restored by a special workshop in Jena by the beginning of April 2007. The operator at the time also completely renovated the dome of the building and the interior of the observatory. On the night of April 24th to 25th, the telescope was hoisted into the observatory in a spectacular action with a 200-ton crane and reinstalled. On May 4, 2007 the ceremonial reopening took place.

Tasks and observations

The domed building, view from the Lindenhof (2009)

The observatory offers astronomical tours - moon , objects in the solar system , star clusters , stars , cosmic nebulae , galaxies - and special events for a wide audience as well as individual tours for schools and groups. The paid public tours will take place from January 1, 2010 on Thursdays, Fridays and Saturdays regardless of the weather. The central location and the observation tower towering over the city of Zurich also provide an unusual view of the city, Lake Zurich and the Alps.

At the same time, the location in the middle of the city of Zurich poses a serious problem: the light pollution hampers observations due to facade lighting shining upwards, so that only a few galaxies and cosmic nebulae are visible. Therefore, observations are practically limited to the moon and planets as well as bright celestial objects.

The Urania-Sternwarte has been operated by the non-profit Urania-Sternwarte Zürich AG since June 2008 , supported by the Astronomical Society Urania Zürich (AGUZ), the Adult Education Center of the Canton of Zürich and the City of Zürich. From 1936 to 2008, the observatory was managed by the adult education center, whose board of trustees provided the capital for the establishment of the new operating company.

Web links

Commons : Urania-Sternwarte Zürich - Collection of images, videos and audio files

Individual evidence

^ From the speech by Government Councilor Regine Aeppli on the occasion of the inauguration of the renovated Urania observatory in Zurich on May 4, 2007.
^ Fred Rihner: Illustrated history of the Zurich old town ; Bosch Verlag, Zurich 1975
↑ The house. Urania Observatory, accessed October 11, 2018 .
↑ ^a ^b The telescope. Urania Observatory, accessed October 19, 2018 .
↑ Swissinfo (September 19, 2004): “Open Heaven” on the long night of the stars , accessed on January 11, 2009
↑ public tours. Urania Observatory, accessed October 10, 2018 .
↑ private tours. Urania Observatory, accessed October 10, 2018 .
↑ Philipp Heck. Dark-Sky Switzerland, archived from the original on February 22, 2012 ; accessed on November 20, 2018 .
↑ Urania-Sternwarte Zürich AG on moneyhouse.ch, accessed on January 10, 2009
↑ partner. Urania Observatory, accessed November 29, 2018 .

47.37435 8.539468Coordinates: 47 ° 22 '27.7 " N , 8 ° 32' 22.1" E ; CH1903: 683,139 / 247640

[1] From the speech by Government Councilor Regine Aeppli on the occasion of the inauguration of the renovated Urania observatory in Zurich on May 4, 2007.

[2] Fred Rihner: Illustrated history of the Zurich old town ; Bosch Verlag, Zurich 1975

[3] The house. Urania Observatory, accessed October 11, 2018 .

[tele-4] The telescope. Urania Observatory, accessed October 19, 2018 .

[swissinfo-5] Swissinfo (September 19, 2004): “Open Heaven” on the long night of the stars , accessed on January 11, 2009

[6] public tours. Urania Observatory, accessed October 10, 2018 .

[7] private tours. Urania Observatory, accessed October 10, 2018 .

[8] Philipp Heck. Dark-Sky Switzerland, archived from the original on February 22, 2012 ; accessed on November 20, 2018 .

[9] Urania-Sternwarte Zürich AG on moneyhouse.ch, accessed on January 10, 2009

[10] partner. Urania Observatory, accessed November 29, 2018 .