New telescope in the Gaisberg observatory

After a 15-month planning, construction and commissioning phase, it is now finally ready. The new 28 inch (710 mm) Newtonian telescope.

After the 24 inch telescope met with some observations on its technical and optical boundaries, the decision was taken about 1 ½ years ago to plan and complete a new, larger instrument. 

Through this the current possible maximum optical aperture and technical feasibility should be the measure for the development of the new telescope. The mechanical assembly and adjustment is now complete and the device is ready for further research work. With this tool it is possible to observe objects that are 36% fainter than was possible with the 600mm telescope.

Another special feature is a large 15 cm refractor. This will be used in future for tours especially for planetary and solar observations. With a special filter, it is now possible to observe solar flares in the Halpha range (red hydrogen line). 

The fork mount, designed and built by Richard Gierlinger, is equipped with friction wheel drives. In conjunction with Heidenhain Winkelmeßgeräten a high dynamic range and accuracy of tracking is made possible. With the 1.8-ton telescope the mass of 1200kg can be moved with only a finger. An automatic damper control for the primary mirror, secondary mirror heating with temperature control, and a focus motor are further devices on of this new telescope.

The telescope is controlled from the viewing room. This contains the computer to control the telescope and the highly sensitive CCD camera. Computer-controlled tracking of the dome is also available. Thus, it is possible to observe with the telescope automatically for several hours. The tracking without the encoder it is in a position to illuminate for several minutes without correction. The rotary encoders that facilitate a relative resolution of approximately 0.01 ° allow the exposure time to be extended accordingly. Currently, a high-resolution spectrograph is in planning. With this it will then be possible to detect exo-planets. Exo-planets are planets outside our solar system.

When it comes to optics, Richard Gierlinger relies on the excellent quality of Alluna Optics as he did with the 600mm telescope. The 50kg main mirror has a diameter of 710 mm with a thickness of only 52 mm. The production of such a thin mirror that must comply with an exact parabolic shape to a few nm (billionths of meters), constitutes a major challenge. To compensate for deflections of the mirror in the telescope incurred because of its own weight, the mirror is positioned axially in a special mechanically, very elaborate version as well as radially mounted according to "Lasalle". Point-like stars to the horizon without astigmatism and spherical aberration show the success of this increased complexity.

There will also be the opportunity for special tours in the Gaisberg observatory. If you are interested please contact Richard Gierlinger. 

For further information on the Gaisberg observatory see  http://www.observatorium.at 

Contact Sternwarte Gaisberg 
Richard Gierlinger 
Telescopes and Mounts 
A.-Stifterstraße 45 
A-4780 Schärding 

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