EUSO-TA – First results from a ground-based EUSO telescope

Abstract EUSO-TA is a ground-based telescope, installed at the Telescope Array (TA) site in Black Rock Mesa, Utah, USA. This is the first detector to successfully use a Fresnel lensbased optical system and multi-anode photomultipliers(64 channels per tube, 2304 channels encompassing a 10.6° × 10.6° field of view) for detection of Ultra High Energy Cosmic Rays(UHECR). The telescope is located in front of one of the fluorescence detectors of the TA experiment. Since its installation in 2013, the detector has observed several ultra-high energy cosmic rayevents and, in addition, meteors. The limiting magnitudeof 5.5 on summed frames ( ∼ 3 ms) has been established. Measurements of the UV night skyemission in different conditions and moon phasesand positions have been completed. The performed observations serve as a proof of concept for the future application of this detector technology.