Draft:North Bohemia Observatory

The North Bohemia Observatory is a defunct astronomical facility in the village of Liboňov, which is part of the municipality of Telnice in the Ústí nad Labem district, in the east of the Ústí nad Labem Region. The observatory was completed in 1929 and served its original purpose until 1945. Since the 1970s it has been in disrepair. Since 2022 it has been restored by the Ústían entrepreneur Vít Musílek.

In 1924, the German University of Prague received a land plot in the Ore Mountains near Telnica as a gift from the landowner Ledeburg to build an observatory on the site.[source?] This place later became one of the most technologically advanced places in the field of astronomy and meteorology. The observatory itself also had an indirect connection to Albert Einstein.

Foundation
In February 1929 a society called "Association of Friends of the Observatory of the German University in Prague" (Vereinigung von Freunden der Sternwarte der Deutsche Universität in Prag) was founded. The aim of the association was to enable the university to carry out scientific activities at the university observatory and its observatory in Liboňov through private funds.

In the spring of 1929, the association purchased a 2800 m² plot of land in Liboňov at an altitude of 480 m on the southern slope of the Ore Mountains, and in the same year an observatory (9 m long and 5 m wide) was built, equipped with all the then modern instruments for observing the sky and the weather. It was a sandstone building designed by František Eis from Ústí nad Labem, the builder was Richard Wagner from Varvažov (son of Karel Wagner, who built the lookout tower on Nakléřovská výšina in 1913). The advantage of the observatory was, unlike Prague, clean air without smoke and dust and the absence of light pollution from city lighting.

Building and equipment
The longitudinal axis was oriented in an east-west direction. The entrance to the building was from the east and opened into a small anteroom measuring 1.1 × 2.75 m. Behind the hallway was a room with a south-facing window. Both were covered by a flat roof. Then came the observation room itself, measuring 5 × 4 m, covered by a semicircular roof with a diameter of 5 m. Two thirds of the roof was on roller shutters and rails. The roof could be extended by means of a mechanical drive to create a gap up to 2 m wide. In the centre of the room, a 200 kg marble slab rested on a 1.55 m high anchored concrete pillar, on which rested a measuring instrument to determine the passage of the constellation through the meridian. The diameter of the objective lens was 6.8 cm and allowed a magnification of 74 times. This measuring instrument had previously accompanied the Austrian polar expedition to Jan Mayen Island in the Greenland Sea from June 1882 to August 1883.

In 1931 the observatory was equipped with instruments transferred from the closed historical observatory from Klementinum. The equipment included a telescope with a 160 mm diameter lens, two thermometers, a rain gauge, a hygrometer and a snow gauge. The observatory was also equipped with a telescope with a 16 cm lens magnifying 300 times. The telescope was mainly used to measure the brightness of the stars. The manufacturer of this telescope and other measuring instruments was Steinheil from Munich. Approximately 15 m south of the main building, on a 1.8 m high structure, there was a device for measuring meteorological data - temperature, humidity and temperature maxima and minima. There was also a device for measuring the duration of sunshine and rainfall or snowfall.

In the summer of 1930, a cellar was built 40 m to the north with an entrance from the east for measuring magnetic declination.

The History
In the summer of 1930, the company purchased another 1,145 m² of land at the western edge of the site.

During the Second World War, the observatory was used for its scientific research work by the German Mining School in Duchcov to measure the Earth's magnetic field for the purposes of mining and surveying work in the mines of the Sub-Krušnohorské Mountains. The school purchased and installed a chronometer for precise determination of the astronomical azimuth of the mines and in April 1942 started the first declination measurements. In December of the following year, a declination variometer of its own design was installed in the basement of the observatory and test observations of the variability of magnetic declination began with three readings per day.

The first crew consisted of observers Dr. Josef Mrázek and Dr. Rudolf Tschilschke. Assistant Mrázek moved to Telnice after the observatory was built (he and his wife lived in Telnice No. 59). He mainly observed variable stars and processed observations of the 1910-1917 culminations. He also carried out magnetic and meteorological measurements. In 1924-1945 he managed the observatory. At that time[when?] the observatory was in urgent need of reconstruction: the roof was rotten and threatened to collapse, there was no connection to the electricity grid and the lights were lit by batteries charged in a distant village. Werner Schaub (who became professor of astronomy on 12 September 1940 thanks to a document signed by Hitler) had the building restored and a separate high-voltage transformer installed for the observatory. In addition, a photometer (originally borrowed from Askania), a measuring table, a modern 1-meter meridian telescope and a new clock from Strasser & Rohde were purchased. Additional funds were used to purchase a library from the estate of Professor Julius Bauschinger (1860-1934), a German astronomer.

After Tschiltsky's sudden death on October 10, 1933, his position remained vacant for several years. Erwin Finlay-Freundlich, an associate and friend of Albert Einstein and briefly a professor of astronomy at Charles University in Prague, stopped magnetic and meteorological observations at the observatory after his arrival in Prague from Istanbul (in 1937), but resumed meteorological observations at the request of the Czechoslovak State Meteorological Institute. During the war, the observatory also served as a meteorological station and a supplement to the observatory at the adjacent Milešovka. Before World War II, the director of the observatory at Milešovka was Prof. Dr. Leo Wenzel Pollak (1888-1964), head of the Geophysical Institute of the German University in Prague. After the occupation of the border area in 1938, the observatory at Milesovka was taken over by the Reich Meteorological Service, from July 1944 as part of the military air service. In the summer of 1945, Dr. Mrázek, who remained at the Telnik Observatory until his death in 1946, held the service and reported the results of the daily measurements to the Meteorological Institute in Prague.

The German university disappeared along with the Nazi Reich in May 1945. As an "institute hostile to the Czech nation", it was legally abolished under Act 122/1945 Coll. by a decree of President Edvard Beneš of 18 October 1945, retroactive to 17 November 1939. The scientific institutes, their facilities and all their property were transferred to Charles University. In the autumn of the same year, Professor Guth and Associate Professor František Link took all the equipment of the German Astronomical Institute (instruments from the observatory in Telnice and the largely preserved library from Luxemburgská Street) to Ondřejov (it is said that in May 1945 a horse-drawn cart loaded with straw crossed the border, under which the most valuable equipment of the Líboňovská observatory was hidden). At the end of 1945 the observatory in Liboňov was closed down and the observatory was taken over by the State Forest Enterprise. In 1951, it rented the dilapidated building as a recreational facility. A year later, the Education Department in Ústí nad Labem applied for the allocation of the observatory, and in June 1953 the building was allocated again for recreational purposes to Jiří Auředník and Miloslav Skál. On 31 May 1954, the observatory was assigned to the national enterprise Meva for civil defence purposes. In September 1956 the observatory was leased to Jarmila Kubíčková from Střekov. Between 1960 and 1969 the observatory was used as a cottage and maintained by the family of František Adam and the family of Eduard Taške.

Extinction of the observatory
Later the construction was taken over by the Tramp settlement of Raraši, which did not take care of the observatory, and after 1970 another tenant let the observatory fall into disrepair. In 1977, the amateur astronomers from Ústí nad Labem were still thinking about repairing it, but they did not get it on lease. Only the outline of the foundations in the middle of the forest remained on the site of the building, which included the observatory, observatory and meteorological station.

Renewal
In January 2022, Vít Musílek and his girlfriend Viky Yang purchased the observatory site and plan to restore the observatory to its original 1929 condition and offer it to the public for stargazing, tours, education and universities for scientific purposes. He spent six months searching for archival materials and managed to find not only the original plans for the observatory, but also the period observatory telescope, which is still located at the observatory in Ondřejov.