Day of the Open Monument on 10 September


The Great Refractor on the Telegrafenberg in Potsdam.

Credit: AIP
Sept. 6, 2023 //

On the occasion of the Day of the Open Monument 2023, the “Förderverein Großer Refraktor e.V.” association will open the doors to the historic refracting telescope on 10 September from 10 am to 6 pm. The members of the association offer guided tours of the astrophysical highlights of the Telegrafenberg as well as a demonstration of the telescope.

Guided tours around the former buildings of the Astrophysical Observatory Potsdam (AOP), one of the predecessor institutes of the AIP, will take place in 2-hour intervals, meeting at the Great Refractor building entrance at 10:15, 12:15, 14:25 and 16:15. The tour ends in the impressive dome hall with a demonstration of the telescope. In between, pictures and films of the restoration of the telescope and its history can be seen.

As a new special highlight, the exhibition of historical instruments in the Great Refractor presents a “light analyser” by Gustav Kirchhoff, which was recently restored as part of a practical project at the Potsdam University of Applied Sciences. Kirchoff developed spectral analysis in the 19th century together with Robert Bunsen, which led to the foundation of astrophysics as an independent field of research. The spectral apparatus on display produced the first solar spectrum. In 1898, the Kirchhoff family left the device to the AOP, which at the time was the first institute in the world to dedicate itself to the spectral analysis of light by name.

The Great Refractor was inaugurated in 1899 by Kaiser Wilhelm II. At the end of the Second World War, the building was badly damaged by an air raid. In the post-war years, committed scientists and engineers made it possible to restore the refractor. It was not until 1968 that scientific work on the instrument ceased completely.

In March 1997, the Förderverein Großer Refraktor Potsdam e.V. was formed to save the disused Great Refractor on Potsdam’s Telegrafenberg from progressive decay. Since the telescope’s ceremonial rededication in May 2006, observation evenings and public events have been held in the dome hall.

The Day of the Open Momument has been coordinated nationwide since 1993 by the German Foundation for Monument Protection, which is under the patronage of the Federal President. Admission to the Great Refractor is free, the Förderverein asks for donations to maintain the telescope.

The key areas of research at the Leibniz Institute for Astrophysics Potsdam (AIP) are cosmic magnetic fields and extragalactic astrophysics. A considerable part of the institute's efforts aims at the development of research technology in the fields of spectroscopy, robotic telescopes, and E-science. The AIP is the successor of the Berlin Observatory founded in 1700 and of the Astrophysical Observatory of Potsdam founded in 1874. The latter was the world's first observatory to emphasize explicitly the research area of astrophysics. The AIP has been a member of the Leibniz Association since 1992.
Last update: 11. September 2023