Overview
The Zimmerwald Observatory (also: Swiss Optical Ground Station) is the largest professional observatory in Switzerland. It hosts 5 telescopes with apertures from 20 cm to 1 m. Its main tasks are twofold: Satelllite laser ranging to determine precise distances to satellites and optical observations, for example of stars and other objects.
Operations
The Observatory is operated by the Astronomical Institute of the University of Bern with a generous contribution by Swisstopo for the geodetic satellite laser ranging. It is used for the research projects of the institute. The following projects give an overview of some of the science carried out at the observatory
- Satellite laser ranging: The 1m ZIMLAT telescope observes satellites during 24 hours per day, weather permitting. It is part of the International Laser Ranging Service (ILRS) where it contributes to the International Terrestrial Reference Frame (ITRF). The ITRF is the precise coordinate system used to measure Earth’s shape, orientation, and movement.
- High-resolution observations: Most of our telescopes are special, in the sense that their tracking speed (and their domes) can be faster than for many other telescopes. Because satellites orbit the Earth, such fast tracking is required due to their relatively high speeds. One of our scientific goals is to improve technical developments and imaging methods to better capture our near-Earth environment. One example of such observations are highly resolved images of the International Space Station.
- Stellar flares: Just like our Sun, stars can have highly energetic explosions. On Earth, the potential effects of major flares include aurora, increased drag on satellites, short circuits, global positioning system malfunctions, and power grid disturbances. On stars, some eruptions have been observed to be thousands of times stronger than those from the Sun, but their mechanisms are still unclear. The Space Weather group is currently constructing a spectropolarimeter to investigate stellar flares in more detail, funded by a SERI-funded ERC Consolidator grant.
The Observatory is also unique in that it is operated 24/7 with two technical staff during the day and student observers at night time. Students from the University of Bern in their 3rd or higher semesters are welcome to approach Prof. Kleint to put their names on a waiting list of interested candidates who are contacted when observing shifts open up. Each student observer is responsible for one shift per week. Many observations are automated, especially during the early morning/evening time window. Special projects, such as our deep sky imaging (examples below), or tracking of special satellites require human observers and their skills in optimizing observations.
