Category of Astronomical Heritage: tangible immovable
Lohrmann-Observatory, Dresden, Germany

Description

Geographical position

Lohrmann-Observatory, Beyer-Bau, George-Bähr-Straße 1d, D-01062 Dresden, Germany

Location

Latitude 51°01’47’’ N, Longitude 13°43’46’’ E, Elevation ...m above mean sea level.

IAU observatory code

040

Description of (scientific/cultural/natural) heritage

Fig. 1. Lohrmann-Observatory, Technical University (TU) in Dresden (1913), (Wikipedia, CC4, Jörg Blobelt)

Architecture of the Lohrmann-Observatory and Beyer building, Technical University Dresden (1913)

The Lohrmann-Observatory, Technical University (TU) in Dresden, was founded in 1913, is part of the Beyer building, erected in 1910 to 1913 by Martin Dülfer (1859--1942) on the border of the campus in the south suburb (Südvorstadt). Dülfer had joined the Dresden reform movement (Hübner et al. 2005), and did not orient himself to the stylistic elements that were dominant in Dresden at that time, but oriented himself more towards northern German building traditions: Red brick, hipped roofs, flat bay windows, narrow windows with narrow pillars are typical, on the other hand there are also a few Art Nouveau elements (Bahr 2011, p. 136). "The aesthetics of the building material" and the "material justice" "demonstrate a new acquisition of form and material that was unique to Dülfer."

Fig. 2a. Beyer-Bau with the Lohrmann-Observatory, Technical University (TU) in Dresden (1913), (Wikipedia, CC4, Jörg Blobelt)

Fig. 2b. Beyer-Bau, entrance hall with exposed concrete middle pillar, Technical University (TU) in Dresden (1913), (Wikipedia, CC4, Jörg Blobelt)

Striking in the cityscape is the observatory tower, which has a dome about 40 meters above street level; this tower is one of "the first high-rise buildings in Germany" (Hübner et al. 2005, p. 10-11) -- 10 floors. In this context, one should mention the Bau 15 (Friedrich Pützer, 1915) in Jena, which is traditionally regarded as the first high-rise building in what is now Germany, but so is sometimes the Narva Tower in Berlin-Friedrichshain, which was completed in 1909.
Dülfer structured the staggered tower of the Lohrmann Observatory on an octagonal base (a very typical feature for observatories since the Tower of the Winds in Athens), which ends at a glass roundabout with a dome above it, with many high windows that alternate with pilaster strips. On the one hand, he wanted to emphasize the verticality, on the other hand, he wanted to achieve an impression of monumentality (Bahr 2011, p. 136).

Bernhard Pattenhausen (1855--1926), professor since 1893, Rector of the TH Dresden (1907/08) and director of the Geodetic Institute, founded the Lohrmann Observatory (1913). The main instrument was the 30-cm-Heyde Refractor. The observatory tower also houses a collection of historical astronomical and geodetic instruments.

Fig. 3. Lohrmann Observatory, named after Wilhelm Gotthelf Lohrmann (1796--1840), painting by Johann Carl Rößler (1775--1845) (credits: TU Dresden)

Lohrmann Institute for Geodetic Astronomy (1961)

The Lohrmann Institute for Geodetic Astronomy, founded in 1961, was an institute of the Technical University (TU) in Dresden, named after the German geodesist and astronomer Wilhelm Gotthelf Lohrmann (1796--1840), which was founded in 1961. Since the institutes were abolished in 1968, it has been known as the Lohrmann Observatory and is also the professorship for astronomy at the TU Dresden. His focus is on geodetic astronomy, celestial mechanics and astrometry.

History

Fig. 4a. Hans-Ullrich Sandig (1909--1979), director of Lohrmann Observatory, 1956 to 1975 (credits: TU Dresden)

Fig. 4b. Klaus-Günter Steinert (1928--2009), director of Lohrmann Observatory, 1975 to 1995 (credits: TU Dresden)

Directors

1893/1913 to 1925 -- Bernhard Pattenhausen (1855--1926)
1956 to 1975 -- Prof. Dr. phil. habil. Hans-Ullrich Sandig (1909--1979), Chair for Geodetic Astronomy; in 1961, founding of the Lohrmann Institute for Geodetic Astronomy,
in 1966 founding of the branch observatory in Gönnsdorf
1975 to 1995 -- Prof. Dr.-Ing. habil. Klaus-Günter Steinert (1928--2009),
in 1975, an astrograph in the Gönnsdorf branch was placed into operation
1995 to 2019 -- Prof. Dr. phil. nat. habil. Michael Soffel (*1953) of Tübingen, now professur for astronomy,
2007 commissioning of the reflector 600/2400 at the new Triebenberg branch (until 2017).
since 2019 -- Prof. Dr. habil. Sergei A. Klioner.

$Lohrmann Observatory, 30-cm-Refractor, made by Gus$

Fig. 5. Lohrmann Observatory, 30-cm-Refractor, made by Gustav Heyde of Dresden (1913), (Wikipedia, CC3, Richard Peter)

Instruments

30-cm-Refractor, made by Gustav Heyde (1846--1930) of Dresden, Mathematisch-mechanisches Institut und Optische Präcizions-Werkstätten (1872--1919)
20-cm-Schmidt-Cassegrain System
25-cm-Schmidt-Cassegrain System
60-cm-Newton Reflecting Telescope (f=2.4m) and CCD-Camera for the observation of asteroids / minor planets
in order to improve the orbital elements, and for the observation of transits of exoplanets.

State of preservation

Fig. 6a. Beyer-Bau with Lohrmann Observatory of TU Dresden (Wikipedia, CC2.5, Hullbr3ach)

Fig. 6b. Restoration of the dome of Lohrmann Observatory, TU Dresden (Wikipedia, CC2, Old Fritz)

Although the attic burned out as a result of WWII, and all the wooden components of the roof truss and the cladding of the observatory tower were lost, only minor changes were made in the post-war years, so that the structure of the building has largely been preserved in its original form.

The building has been renovated since 2018, including the tower. After the historic refractor was removed in 2016 and brought to Jena for restoration, work starts now with the observatory tower. The spectacular event on March 14, 2022, was the dismantling of the observatory dome (it weighs 12 tons and has a diameter of around 8.5 meters) with a 200 ton crane. Until early 2023, the dome will be repaired on the ground; then the Beyer building is scheduled to reopen in 2024.

Comparison with related/similar sites

The Lohrmann Observatory tower with a dome about 40 meters above street level, is one of "the first high-rise buildings in Germany" (Hübner et al. 2005, p. 10-11) -- 10 floors. In this context, one should mention the Bau 15 (Friedrich Pützer, 1915) in Jena, which is traditionally regarded as the first high-rise building in what is now Germany, but so is sometimes the Narva Tower in Berlin-Friedrichshain, which was completed in 1909.

Threats or potential threats

no threats

Present use

The Lohrmann-Observatory, TU Dresden, is still used for astronomy, today especially for space astrometry.
The Lohrmann Institute has has for public outreach also a planetarium.

Astronomical relevance today

The focus of the Lohrmann-Observatory, TU Dresden, is on geodetic astronomy, celestial mechanics, astrometry (determination of the coordinates of asteroids), and transit photometry of exoplanets.

References

Bibliography (books and published articles)

Bahr, Christian: Architekturführer -- die 100 wichtigsten Dresdner Bauwerke. Berlin: Jaron 2011, p. 136-137.
Birmingham, J.: Review (Lohrmann’s Lunar Map). In: Astronomical Register 16 (1878).
Gantz, Holger: 100 Bauwerke in Dresden. Ein Wegweiser zu Bauwerken von historischem und baukünstlerischem Rang. Regensburg: Schnell & Steiner 1997.
Hänseroth, Thomas: 175 Jahre TU Dresden. Band 2: Wissenschaft und Technik -- Studien zur Geschichte der TU Dresden. Hrsg. von Reiner Pommerin. Köln: Böhlau 2003.
Helfricht, Jürgen:: Astronomiegeschichte Dresdens. Dresden: Hellerau-Verlag 2001.
Hübner, Ulrich et al.: Symbol und Wahrhaftigkeit. Reformbaukunst in Dresden. Husum: Verlag der Kunst Dresden Ingwert Paulsen jun. 2005.
Lohrmann, Wilhelm Gotthelf: Topographie der sichtbaren Mondoberfläche. Dresden, Leipzig 1824.
Lohrmann, Wilhelm Gotthelf: Mondcharte in 25 Sectionen und 2 Erläuterungstafeln. Mit beschreibendem Text von Johann Friedrich Julius Schmidt. Leipzig: J.A. Barth 1878.
Petschel, Dorit: 175 Jahre TU Dresden. Band 3: Die Professoren der TU Dresden 1828--2003. Hrsg. von Reiner Pommerin. Köln: Böhlau 2003.
Pommerin, Reiner (ed.): 175 Jahre TU Dresden. 3 Bände. Hrsg. im Auftrag der Gesellschaft von Freunden und Förderern der TU Dresden e.V. Köln, Weimar, Wien: Böhlau 2003.
Pommerin, Reiner: 175 Jahre TU Dresden. Band 1: Geschichte der TU Dresden 1828--2003. Hrsg. von Reiner Pommerin. Köln: Böhlau 2003.
Potthoff, Helfried: Nachruf. Klaus-Günter Steinert †. 1928--2009. In: Mitteilungen der Astronomischen Gesellschaft 93 (2010), p. 11-14.
Sandig, Hans-Ullrich: Astronomie für Geodäten. Berlin: Verlag Technik 1970. Dresden 1971.
Steinert, Klaus-Günter: Obituary -- Sandig, Hans-Ullrich. In: Astronomische Nachrichten 301 (1980), p. 39 (1980AN....301...39S)