System Description and First Light Curves of the Hungarian Automated Telescope, an Autonomous Observatory for Variability Search

Having been operational at Kitt Peak for more than a year, the prototype (HAT-1) of the Hungarian Automated Telescope (HAT) has been used for an all-sky variability search of the northern hemisphere. This small autonomous observatory is recording the brightness of stars in the range of I_C~6-13 mag with a telephoto lens and its 9^deg×9^deg field of view, yielding a data rate of ~10⁶ photometric measurements per night. We give brief hardware and software descriptions of the system, controlled by a single PC running RealTime Linux OS. We provide an overview of site-specific details and quantify the astrometric and photometric capabilities of HAT. As a demonstration of system performance, we give a sample of 60 short-period variables in a single selected field, all bright, with I<13 mag, where only 14 were known before. Depending on the observing strategy, a search for extrasolar planet transits is also a feasible observing program. We conclude with a short discussion on future directions. Further information can be found at the HAT Web page.3