The 2m telescope

The observatory is running a ZEISS  2m telescope ("Alfred-Jensch-Teleskop") which can be used in three different optical configurations: 

The spherical primary mirror of the telescope has a focal length of 4m. All mirrors are made of zero-expansion glass ceramic material ("SITALL").

TV-Guider is used for the Coudé spectrograph as well as for the guiding telescope. 

The Schmidt telescope modus

The Schmidt telescope of the TLS is the largest Schmidt camera of the world. It is characterized by the following parameters:

   Diameter of the primary:                 2.00m
   Diameter of the corrector plate:     1.34m
   Focal length:                                   4.00m
   Field of view (unvignetted):             3.3° x 3.3° (maximum)
   Scale:                                             51.4 arcsec/mm 

The following auxiliary devices are available: 

For more information concerning the Schmidt system, please contact Helmut Meusinger (<> ).

The Quasi-Cassegrain or Nasmyth telescope modus

The Nasmyth system has a focal length of 21 meters. Because of the spherical primary, the usable field of view is only 10...20 arcsec. Using a flat mirror the light is directed through the declination axis to one of two external Nasmyth focus stations. For the spectroscopy of faint objects a spectrograph is available in the Nasmyth focus. 

For more information concerning the Nasmyth spectrograph, please contact Helmut Meusinger (<>) or Holger Lehmann (<>).

The Coudé telescope mode

The Coudé system has a focal length of 92m (f/46). The Coudé spectrograph uses a collimated beam of 150mm in diameter. Formerly, four spectrograph cameras (focal lengths: 350mm, 700mm, 1400mm, and 2800mm) and various gratings (typically 600 grooves/mm) were used providing linear dispersions from 2 to 24Å/mm. Nowadays the Coudé spectrograph is mainly used in the Echelle mode.

   Echelle spectrograph

For more information concerning the Coudé spectrograph, please contact Holger Lehmann (<>) or Eike Guenther (<>).