HAMBURGER STERNWARTE (OBSERVATOIRE DE HAMBOURG)

Located on the eastern outskirts of the city, the Hamburg Observatory operates several optical and radio telescopes (radio telescopes) for research and teaching purposes. Only some of them are located in the Bergedorf area, including the Oskar-Lühning telescope, the Kleines Radioteleskop and several small optical telescopes. These are the "historical" telescopes that are used for public observing evenings. The Hamburg Observatory has been located in Bergedorf since 1909, but it was originally established in the city center as early as 1802 by the German astronomer Johann Georg Repsold. Among the astronomical activities of the observatory were, as was often the case at that time, the measurement of the position of the stars and the determination of the exact time, two parameters that were extremely important, especially in the context of commercial navigation and the precision in the tracing of maritime routes. Other studies, more secondary, were nevertheless carried out on the spot, research of new comets, nebulae, etc. The apogee of its activity was probably the setting in operation of a clock system from 1876, a "time ball" which will be used later also for the calibration of the speaking clock. In 1867, the observatory received subsidies to acquire a powerful astronomical telescope with a diameter of 270 mm, which is still in use today. At the beginning of the 20th century, the increasing pollution in the city center of Hamburg forced an important decision to move the observatory to a better location. In 1909, the Bergedorf area was chosen, and in 1912 the new observatory was officially inaugurated. For the record, the old observatory was completely demolished and the Hamburg History Museum was built in its place! The choice of Bergedorf proved to be worthwhile because during the following decades, the activities within the observatory multiplied: astrometry, creation of star catalogs, photographs of celestial objects, etc. The biggest telescope of the site, of 1 m in diameter, allowed to realize beautiful discoveries among the myriads of stars of our Milky Way! Other prestigious telescopes located at Bergedorf were moved to much better skies, notably to the Spanish observatory of Calar Alto. This was the fate of many historical European observatories which, having been at the peak of astronomy at the end of the 19th century and until the 1950s, were "decommissioned" because of the severe degradation of their observation site, due to light and atmospheric pollution. Since June 2021, the Hamburger Sternwarte is a candidate for inclusion in the Unesco World Heritage List.

Today, the Hamburg Observatory is very active in the field of popularizing astronomy to the general public. This is demonstrated by the numerous guided tours, thematic workshops (telescope construction, astrophotography, etc.), observation evenings and other open days organized throughout the year. Program and reservations on the website. A great opportunity to discover an observatory that is not well known (by French amateurs anyway), but that has a very fascinating history.