Astrophysikalisches Institut Potsdam Sonnenobservatorium Einsteinturm

Optical Solar Physics - Solar Observatory `Einsteinturm'

Research programmes

Solar research in Germany started in 1874 when the Potsdam Astrophysical Observatory was established. Half a century later the Einstein Tower was inaugurated as the first tower telescope in Europe. Since that time Potsdam astrophysicists have at their disposal a powerful solar research facility, including an efficient spectrograph which was one of the greatest equipments of that time. More than 50 years ago it was the first place in Europe where solar magnetic fields were measured by means of spectro-polarimetric methods. All of the phenomena of solar activity are caused by the interaction of the turbulent solar plasma with magnetic fields. This is why the determination of the structure and development of magnetic fields is a key problem for the investigation of activity phenomena and still the main topic in the research program of solar physicists at Potsdam.

Nowadays the Einstein Tower is equipped with a double spectrograph and two photoelectric polarization analyzers which allow to determine the spatial distribution of the magnetic field vector and its gradient. In order to get data with the highest spatial resolution, the experiences and methods worked out in Potsdam are brought into action at the German vacuum solar telescopes in the Spanish Observatorio del Teide at Tenerife. A participation in satellite experiments renders accessible special data which are not within reach from ground-based observatories.

Due to its location in central Europe the Einstein Tower attains an average spatial resolution of 3'' only. Owing to its permanent availability, however, its use is an indispensable completion of the measurements by means of the great Tenerife telescopes and satellite experiments and comprises the following topics:

• Participation in international measuring campaigns, e.g. within common programmes with extraterrestrial projects such as SOHO or CORONAS;
• simultaneous measurements during the observing programmes at Tenerife, gathering data from larger areas on the Sun and longer time periods;
• development and tests of new post-focus equipments (infrared receivers, spectro-polarimeters etc.) for a later application at Tenerife;
• education of students for a later work at the great instruments.

Jürgen Staude

Some introductional texts are also available in German only. Please refer to the German version of this page.