Very high energy gamma astronomy at the South Pole

The Air Cherenkov Technique (ACT) is a very important tool to extend our present knowledge on very high (VHE) gamma emission from compact astrophysical sources. To overcome the intrinsic limitations of this technique, we are testing the possibility of installing an ACT Telescope at the South Pole. This site is ideal for several reasons: The long polar night permits almost continuous observation of a source (up to 400 hours per month and 1700 hours per year). The circumpolarity of the sky simplifies data analysis. The region of the sky is particularly rich in candidate sources. To test the effectiveness of the site, we installed a prototype telescope in the austral summer of 1989-90. The prototpye started to operate in May 1990. (orig.)