Observation Runs

The scientific main interest of our telescope group is the determination of orbital periods of binary systems, especially of cataclysmic variables. These are close binary systems in which matter from one star (donor) flows to the other star (accretor). Normally an accretion disk is built around the accretor. These systems show many astrophysical phenomena which often lead to a variability of their light curve. One observes for example nova outbursts (thermonuclear explosions on the surface of the accretor) and dwarf nova outbursts (strong increase of the temperature and luminosity of the accretion disk) or variable mass transfer from the donor onto the accretor.

Furthermore we try to determine pulsation periods of pulsating stars. From those pulsation periods one can learn much about the inner structure of the star (asteroseismology).

The basis for the determination of orbital and pulsation periods is the generation of the light curve of an object. During the night, or several nights, one takes exposures of the object and determines the brightness of the object in every single exposure, dependent on the time, to get the light curve. This light curve is analysed with software packages, developed at our institute, to detect periodic variabilities.