The QUEST RR Lyrae survey.: I.: The first catalog

With the 1 m Schmidt telescope of the Llano del Hato Observatory and the QUEST CCD camera, 380 deg(2) of the sky have been surveyed for RR Lyrae variables in a band 2.degrees3 wide in declination (centered at delta = -1degrees) and covering right ascensions from 4.(h)1 to 6.(h)1 and from 8.(h)0 to 17.(h)0. The bright limit ( due to CCD saturation) and the faint limit are V similar to 13.5 and similar to 19.7, respectively, which correspond to similar to 4 and similar to 60 kpc from the Sun. We present a catalog of the positions, amplitudes, mean magnitudes, periods, and light curves of the 498 RR Lyrae variables that have been identified in this region of the sky. The majority of these stars (86%) are new discoveries. The completeness of the survey has been estimated from simulations that model the periods and light curves of real RR Lyrae variables and take into account the pattern of epochs of observation. While the completeness of the survey varies with apparent magnitude and with position, almost everywhere in the surveyed region it is quite high (> 80%) for the type ab RR Lyrae variables and between 30% and 90% for the low-amplitude type c variables.