The Practice Observatory

The practice observatory is located on the roof of the institute for experimental and applied physics.



The Telescope

The main instrument is a reflecting telescope with a diameter of 25 cm. It can be used with a secondary mirror with a focal length of either f= 2000 mm in Ritchey Chretien focus, or f= 3750 mm in Cassegrain focus. The alignment is done semi-automatically with an electronic coordinate display. The telescope mount has autotracking in order to compansate for the Earth's rotation. For more precise alignment of the objects there is a second refractor (110 mm opening and 600 mm focal length).


The CCD camerateleskopx.gif

In order to take pictures of objects, a CCD camera of the type ST-8XME is used. The CCD chip has a size of 1530 x 1020 pixels and its RC focus provides 22.4 x 15.2 square arcminutes field of view. Using different standardized color filters, colored images are also a possibility (see the gallery). A second CCD chip allows an additional autotracking for long exposure shots. The camera is connected to a laptop in order to save data and control the camera. Afterwards, the pictures can be copied to a computer at the institute where python scripts for data reduction are available.


The Spectrograph

The grating spectrograph allows to take images of star spectra with two different dispersions, using the CCD camera as the detector. The wavelength calibration of the spectra is done with the emission spectrum of a HgAr spectral lamp.