System description and first light-curves of HAT, an autonomous observatory for variability search

Having been operational at Kitt Peak for more than a year, the prototype of the Hungarian Automated Telescope (HAT-1) has been used for all-sky variability search of the northern hemisphere. The small autonomous observatory is recording brightness of stars in the range of I~6--13m with a telephoto lens and its 9x9 degree field of view, yielding a data rate of ~10^6 photometric measurements per night. We give brief hardware and software description of the system, controlled by a single PC running RealTime Linux operating system. We overview 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 < 13m, of which only 14 were known before. Depending on the observing strategy, 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 homepage: http://www-cfa.harvard.edu/~gbakos/HAT/