Largest European Solar Telescope Starts Test Operations

The Gregor Solar Telescope saw sunlight for the first time at 14:55 UT on Thursday, March 12, 2009. This picture shows the image of the Sun on the field stop at the focus of a 1m primary mirror which was installed during the preceding two weeks.

This incident marks the beginning of the final phase of integration of the Gregor telescope and its instruments, which is expected to be completed in summer 2010. This is the first time that the entire optical train of the telescope sees sunlight.

The primary mirror is a silicon carbide mirror which was developed as a demonstrator for a 1m solar space telescope. Its purpose is to perform optical alignment tests and to test the main mirror air cooling system, which is critical for the telescope's operation. It will also serve to set up the first generation of post-focus instruments later this year, as well as the adaptive optics system which compensates imperfections in the image arising from turbulence in the Earth's atmosphere.

Scientific observations will not be made in this test and integration configuration. They require the final 1.5m primary mirror which is currently being fabricated by Zeiss and will be delivered in April 2010. The current 1m mirror has the same focal length as the 1.5m mirror, which is why its integration into the telescope is relatively simple.

Gregor is one of the telescopes at the Teide Observatory of the Instituto Astrofisica de Canarias on Tenerife. It is operated by the Kiepenheuer-Institut für Sonnenphysik on behalf of a consortium of German research institutes, including two institutes of the Leibniz Association – the Kiepenheuer-Institut and the Astrophysical Institute Potsdam.

Contact:
Dr. habil. Hubertus Woehl
Kiepenheuer-Institut fuer Sonnenphysik (KIS)
Schoeneckstr. 6
79104 Freiburg
GERMANY
Phone: +49-761-3198-174 (or -3198-0 secretary)
E-mail: hw@kis.uni-freiburg.de