Hamburg observatory
| Hamburg observatory | |
|---|---|
 Main building of the Hamburg observatory |
|
| founding | 1909 (1802) |
| IAU code | 029 |
| Type | Observatory |
| Coordinates | 53 ° 28 '49.6 " N , 10 ° 14' 27.7" E |
| place | Hamburg-Bergedorf |
| operator | University of Hamburg |
| Website | Hamburg observatory |
The Hamburg observatory is a historical research observatory operated by the University of Hamburg . It has been on the Gojenberg in the Hamburg district of Bergedorf since 1909 .
history
First observatory at Stintfang
Johann Georg Repsold , the founder of the Hamburg observatory, set up his own small observatory on the Albertus bastion at Stintfang in 1802 . Repsold, who had learned hydraulic engineering from Reinhard Woltman in Ritzebüttel , the Hamburg suburb near Cuxhaven , was responsible for the fire brigade and the maintenance of the lighthouses from 1799 onwards as the municipal “syringe master” . In addition to his professional activity, he devoted himself in particular to the construction of astronomical observation devices, which were of very good quality. In 1811, during the time of the Napoleonic occupation, the observatory had to be demolished. In the same year Repsold submitted the first petition to the Hamburg Senate to establish a municipal observatory, which he repeated in 1820 together with Jonas Ludwig von Heß and Johann Theodor Reinke .
Second observatory on Holstenwall
In the same year Repsold explained to the Hamburg Senate the need to set up an observatory, combined with a new navigation school. The Henricus Bastion at the Millerntor was determined as a suitable location. It was not until 1824 that the Senate agreed on the condition that Repsold provided the observation instruments free of charge. The construction of the observatory was partially completed in 1826. The observatory consisted of a two-wing structure with two wooden domes on the roof. Half of the building was used by the navigation school.
After Repsold was killed in fire fighting in 1830, the Senate decided to take over the observatory as a state institute after private financing of the operating costs was secured. The new director was the astronomer Karl Rümker , who until then had headed the Parramatta observatory ( Australia's only observatory). Repsold's sons and later his grandchildren built the company " A. Repsold & Söhne " in Hamburg into one of the world's leading companies for optical instruments. The company existed until 1919. When Rümker retired in 1857 for reasons of age, his son George Rümker took over the management. After George Rümker's death in 1900, Richard Schorr was appointed director.
The main task of the observatory, in addition to astronomical observation and astrometry , was the exact determination of time . This was determined using a meridian telescope . The clock system of the observatory controlled several normal clocks , later the time ball of the Hamburg port and the telephone time announcement .
At the end of the 19th century, the site was severely affected by increasing air and light pollution as well as vibrations, so that relocation was necessary. The Gojenberg in Bergedorf was set as the new location.
After the observatory was demolished, the Museum of Hamburg History was built here in 1914 .
Today's observatory in Bergedorf
Construction of the new observatory began in 1906, most of the buildings were completed in 1909 and the first telescopes were installed . The observatory was officially inaugurated in 1912.
It was initially equipped with a meridian circle , a large refractor with a 60 cm opening from " Repsold & Sons ", a Newton telescope from Carl Zeiss with a main mirror 1 m in diameter, a double astrograph from Zeiss for astrophotography and the telescopes from the old observatory.
In the following years several extensive star catalogs were created, including the AGK2 catalog. The physical properties of the stars were examined using the double astrograph . Walter Baade carried out studies of the distribution of stars in the Milky Way and other galaxies .
Between 1905 and 1929 the observatory carried out several expeditions to observe solar eclipses , including to Algeria , Mexico , Sweden and the Philippines .
From 1926 the optician and telescope designer Bernhard Schmidt worked as a freelancer at the observatory. Here, in 1930, Schmidt succeeded in manufacturing an aspherical correction lens and thus the invention of the " Schmidt mirror ". The extremely bright and coma-free wide-angle camera right up to the edge of the photo plate is one of the sweeping innovations in astrophotography of the 20th century. A planned large Schmidt mirror could only be realized after the war.
In 1941, Richard Schorr retired from office due to old age and Otto Heckmann took over the management of the observatory. Since the beginning of the Second World War, it has only carried out tasks for the military as a "war-important institute", in particular position calculations for military navigation and observation of solar activities. The entire area of the observatory in Bergedorf survived the war almost completely unscathed.
With Heckmann's appointment, the observatory defended itself against the influence of the National Socialist German Lecturers' Association on the staffing. Otto Heckmann remained an opponent of the ideological “ German Physics ”; he successfully participated in the so-called “Munich Religious Discussion” in 1940 with Carl Friedrich von Weizsäcker . After 1945, as director of the Hamburg observatory, he was also an internationally respected astronomer.
In 1954 the long-planned large "Hamburger Schmidt-Spiegel ", designed by Heidenreich & Harbeck , was put into operation. A system for aluminum vapor deposition on telescope mirrors was also set up, in which mirrors up to a diameter of 1.5 m can be coated. The plant is still in operation today.
In 1962 Otto Heckmann was elected the first Secretary General as one of the founding fathers of the European Southern Observatory . He set up the first ESO headquarters in the city center of Bergedorf, with which he moved to Garching near Munich in 1975 . In July 1968 he was retired. In 1968 the observatory was accepted as an institute in the physics department of the University of Hamburg .
In 1971 a zone astrograph from Carl Zeiss was installed. In 1976 the large Schmidt mirror was relocated to the German-Spanish Calar Alto Observatory in southern Spain . In its place, a large Ritchey-Chrétien-Cassegrain telescope with an opening of 1.20 m was put into operation as the "Oskar Lühning telescope" in Bergedorf . Later it was equipped with modern control and recording technology and it is still used for teaching and research purposes.
Schmidt Museum
In the basement of the main building is the Schmidt Museum , in which devices by Bernhard Schmidt are exhibited, including the first Schmidt mirror he designed .
Library
The library, which has over 70,000 volumes, is housed in the main building and contains all the important astronomical publications from the last 200 years.
Monument protection
In 1996 the entire observatory was placed under a preservation order, and in 1999 the main building was renovated.
In 2008, Minister of State for Culture Bernd Neumann included the observatory in the promotion of nationally important cultural monuments. In addition, an application for a UNESCO World Heritage Site is currently underway , in which the Hamburg observatory is nominated together with comparable observatories from other countries.
Publicity
In addition to astrophysical teaching and research, the Hamburg observatory regularly offers astronomical lectures, public observations of the sky and open days. In cooperation with the school authorities, workshops for schools and holiday courses are offered in the project “Astronomy Workshop”.
Visitor center
The park area of the observatory has been freely accessible to the general public on Saturdays and Sundays. The planetary path and the buildings of the observatory are provided with information boards. The visitor center in the restored building of the 1-meter mirror offers lunch from Wednesday to Friday and a café at the weekend. This is where the regular guided tours of the observatory begin; the historical library and a scale model of the Hamburg time ball can also be viewed in the main building .
Support association
Due to the difficult economic situation of the observatory, the "Förderverein Hamburger Sternwarte eV" was founded in 1998. The goals of the association are primarily to preserve the buildings and astronomical equipment of the observatory in accordance with the preservation order. In addition, he supports astronomical public relations work and aims to use parts of the site as a public observatory in the future . The application for a World Heritage Site , which has been running since 2012, is an important focus of work.
Instruments
Big refractor
The large refractor has a lens opening of 60 cm and a focal length of 9 m. It is one of the largest refractors in Germany and is mainly used today for public observations of the sky. On the main telescope there is a guide telescope with an opening of 18 cm and a focal length of 8.5 m as well as a finder scope with a 10 cm opening.
The domed building was erected in 1909 by Carl Zeiss , while the tube and mounting were completed in 1911 by Repsold & Sons . The two-lens optics could not be delivered by the Munich company Steinheil until 1914 , as the production of large, fault-free glass lenses was very problematic (see article on giant telescopes ). Because the lens designed for visual observation was unusable for astrophotography (at that time the photographic plates were only sensitive to blue), a photographically corrected lens was made by Steinheil in 1925, which could be used if necessary. The floor of the dome is designed as a lifting platform and can be raised by 4.5 m by means of electric motors and wire rope hoists. This allows the observer to look comfortably into the eyepiece in any position of the telescope without having to climb a ladder or use a height-adjustable astronomical chair .
The large refractor was initially mainly used for visual observation of the planets and variable stars . Later, open star clusters and variable stars were investigated using photographic methods and spectroscopic studies were carried out. During the Second World War the dome and lifting platform were hit by an incendiary bomb . The bomb got stuck in the cellar without igniting.
After the war the refractor was used to measure the sun's magnetic field and for photometry . In 1969, a particularly fast-reacting photometer was installed with which the light fluctuations of the pulsar in the Crab Nebula could be monitored. By evaluating the star coverages by the moon , the angular diameters of stars could be determined. From the 1970s the refractor was used for astrometry .
1 m reflecting telescope
At the beginning of the 20th century, mirror telescopes became increasingly important. As they - in contrast to the refractors - have no color defects, they are particularly suitable for astrophotography. The large, 26-ton reflector telescope was initially manufactured by Carl Zeiss in Newton construction with a 1 m mirror diameter and 3 m focal length. The main mirror sagged under its own weight so that Zeiss had to manufacture a new mirror mount. When it was commissioned in 1911, the telescope was the fourth largest in the world and the largest in Germany. The mount - a so-called "relief mount" - is a specialty. Declination and right ascension axes are hollow. Strong iron bars in the axes take up the weight of the telescope and relieve the bearings of the axes, whereby a particularly precise and friction-free movement and tracking is achieved.
By 1920 over 1,700 photographic plates had been exposed, which were mainly used to search for and determine the orbit of minor planets and comets . During this time 30 new minor planets and one comet (1918III Schorr) were discovered in Bergedorf, two periodic comets were rediscovered. From 1920, Walter Baade photographed star clusters, gas nebulae and galaxies with the telescope, publishing groundbreaking work on globular clusters and the distribution of stars. In addition, he succeeded in discovering two galaxy clusters , a comet (1922II Baade) and several minor planets, including (944) Hidalgo .
After Baade left for the USA in 1931, the telescope was mainly used again for the observation of small planets and comets. In addition, the emission line spectrum of the Orion Nebula was examined annually . In order to optimize the telescope for spectroscopy, it was converted to the Nasmyth design with secondary and tertiary mirrors in 1947 , thereby extending the focal length to 15 m. Several thousand star spectra had been recorded by 1972.
In the 1980s, the device was still used for internship purposes, then only for public observations until it was shut down. The support association of the observatory enabled a comprehensive and careful restoration and renovation of the telescope and dome building. The 1 m mirror has been usable again for astronomical research and public observations since 2014.
Lippert telescope
The large double astrograph ( Lippert telescope , named after its founder Eduard Lippert ) originally consisted of three refractors for astrophotography and two refractors that served as a guide telescope . The telescope and the 7 m observation dome were completely built by Carl Zeiss . On one side of the declination axis, a so-called "normal astrograph", a standardized telescope with a 34 cm aperture and 3.4 m focal length and a guide refractor with 23 cm aperture and 3.4 m focal length were attached. On the other side were two astrographs of equal size with a 30 cm aperture and 1.5 m focal length and a guide refractor with 20 cm aperture and 2.6 m focal length. Such an arrangement of the same instruments was common at the time in order to be able to distinguish plate defects from real objects or to make recordings in different color areas. The normal astrograph was put into operation in 1911, the two short-focal length astrographs not until 1914.
Extensive spectroscopic investigations were carried out with the Lippert telescope. As part of the Bergedorf spectral survey, recordings were made in 115 Kapteyn calibration fields from 1923 to 1933, 173,500 stars were classified. The result was published as a catalog in five volumes between 1935 and 1953. In addition, variable stars as well as minor planets and comets were examined. Numerous variable stars, several minor planets and four comets were discovered (including 1925 II P / Schwassmann-Wachmann 1 ).
In the course of time the Lippert telescope was completely revised and rebuilt. In 1957 the normal astrograph and the larger guide telescope were replaced by a reflecting telescope with a 60 cm aperture and 3 m focal length, which had been manufactured by Bernhard Schmidt and originally formed one half of a so-called "double reflector". In 1974 it was equipped with Cassegrain optics with a focal length of 9 m. In the same period, the double aastrographs were dismantled. Today the telescope is used for training purposes, for school internships or for public observations of the sky.
Equatorial
The refractor called equatorial with a 26 cm aperture and 3 m focal length is the oldest telescope in Bergedorf. It is an equatorial telescope that is equipped with large pitch circles and reading microscopes to determine precise star positions outside the meridian . However, the measurement accuracy of these telescopes is less than that of meridian telescopes. The equatorial of Bergedorf is the largest built telescope of its kind. It was manufactured in 1867 by the company " A. Repsold & Sons " and placed in the second observatory on the city wall.
Minor planets and comets were observed and the positions of foggy objects were determined. In 1909 it was installed in the new Bergedorf observatory in a newly constructed building, whereby the original dome could still be used. In the dome there is an observation chair that can be moved around the telescope by means of cables so that the observer does not have to get up.
After the new telescopes were put into operation, the equatorial was initially only rarely used. From 1946 to 1977 the amateur astronomer Max Beyer systematically observed comets and variable stars. His precise and careful work was published regularly in the " Astronomische Nachrichten ".
The equatorial is still operational today. After the renovation of the building, which was completed in 2005 by the Friends of the Hamburger Sternwarte eV, the dome can also be opened again.
Zone astrograph
The zone astrograph is a refractor with an aperture of 23 cm and a focal length of 2.05 m, which is used for the precise determination of star positions and their own movement. Its lens consists of a five-lens system with excellent imaging properties. Over 2,000 photographic plates have been taken since 1975. The determined star positions were used in numerous projects, for example when surveying the sky with the Hipparcos satellite .
Oskar Lühning telescope
The large Ritchey-Chrétien telescope ( Oskar Lühning telescope , named after the son of its founder, a rector from Bergedorf) is the largest telescope at the Hamburg observatory and one of the largest telescopes with a 1.20 m main mirror and 15.60 m focal length Germany. It was placed on the mount of the original large Schmidt mirror in 1975. The optics were made in England. In the 1980s the telescope was used for photometry and spectroscopy of variable stars. From 1998 to 2001 the telescope was overhauled and rebuilt and equipped with computer control and a CCD camera.
Salvador mirror
The instrument known as the Salvador mirror (the origin of the name is unclear) is a Cassegrain telescope with a mirror diameter of 40 cm and a focal length of 8 m. The telescope was first used in 1960, but had to be revised by the manufacturer due to optical defects. From 1967 to 1970 the telescope was used for photometry at a branch of the observatory on the Peloponnese in Greece . Back in Germany, the telescope was not put into operation until the 1980s. Today it is mainly used by the support association of the observatory.
Individual evidence
literature
- Otto Heckmann: The work of the Hamburg observatory in Bergedorf . In Lichtwark No. 7. Bergedorf, 1953. See now: Verlag HB-Werbung, Hamburg-Bergedorf, ISSN 1862-3549 .
- Lars Quadejacob: Centennial Science Park: Bergedorf Observatory . In: Yearbook Architecture in Hamburg 2011, Junius Verlag, Hamburg 2011, pp. 138–147.
- Agnes Seemann: The Hamburg observatory in Bergedorf . In: Lichtwark booklet No. 73. Verlag HB-Werbung, Hamburg-Bergedorf, 2008. ISSN 1862-3549 .
- Jochen Schramm, Thomas Schramm: The Bergedorf Observatory in the Third Reich . In: Lichtwark booklet No. 58. Ed. Lichtwark Committee, Hamburg-Bergedorf, 1993.
- Jochen Schramm: Stars over Hamburg - The history of astronomy in Hamburg , 2nd revised and expanded edition, Kultur- & Geschichtkontor , Hamburg 2010, ISBN 978-3-9811271-8-8
- Gudrun Wolfschmidt : Astronomical Patronage (Proceedings of a Symposium in October 2004), Chapter 2 (p. 31 to 52) ( limited preview in the Google book search)
Web links
- University Institute Hamburg Observatory
- Visitor center of the Hamburg observatory (private site)
- Friends of the Hamburg Observatory (FHS)
- Schmidt Museum of the Hamburg observatory
- Current events in the Astronomy Park
- By telescope into Sternzeit , an article about the Hamburg observatory at Monumente Online
- Bergedorfer Zeitung of January 14, 2009: "As important as Michel"
- The history of the Hamburg observatory (private site)
- private side