The First G-APD Cherenkov Telescope

The First G-APD Cherenkov Telescope (FACT) is the first imaging atmospheric Cherenkov telescope using Geiger-mode avalanche photodiods (G-APDs) as photo sensors. The rather small, low-cost telescope will not only serve as a test bench for this technology in Cherenkov astronomy, but also monitor bright active galactic nuclei (AGN) in the TeV energy range.