Your own observatory. That was the promise with which the sovereign King Frederick William IV of Prussia enticed the astronomer Frederick William Argelander to Bonn in 1836. A few years later, construction began. For this, the astronomer joined forces with the university building inspector Peter Josef Leydel. Within four years, they had built the observatory in the classical style. When completed, the observatory was one of the most modern observatories of its time. It was optimally equipped for astronomical work, for example with telescopes, barometers and astronomical pendulum clocks. The observatory’s heliometer can be seen today in the University Museum in Bonn.
During his time in Bonn, the astronomer Angelander recorded the position and brightness of well over 300,000 stars as part of the ‘Bonn Survey’.
At the time the observatory was built, it was still located far outside the city of Bonn. This meant that it was largely protected from light pollution. However, due to the expansion of the city, the observatory is now located in the city itself and is only a reminder of old times. In recognition of this, the Old Observatory was named an Outstanding Astronomical Heritage Site by the International Astronomical Union in 2018.
Information on events: https://www.volkssternwarte-bonn.de/
Photo: Telescope of an observatory. Credits: Pixabay/FSchiller.
