First astronomical results from S-Cam

Abstract S-Cam is a cryogenic camera for ground-based astronomy based on a 6×6 array of Superconducting Tunnel Junctions (STJs). The camera has been designed as a technology demonstrator, aiming to prove the potential of this new generation of single photon counting detectors at a ground-based telescope. In this article we provide an overview of the detector performance, a description of the S-Cam system and a summary of the test results. The first astronomical data obtained at the William Herschel Telescope (WHT) in La Palma (Canary Islands, Spain) are also described.