Photometric Parameters of RR Lyr Variable Stars in the Galactic Bulge

Abstract

We present a complete set of OGLE photometric measurements for 214 RR Lyrae variables in the Galactic bulge, based on four observing seasons: 1992-95. These are mostly I-band measurements, with some V-band observations obtained mainly in 1995. Based on this material we construct the Fourier decomposition of the I-band light curves and investigate different types of RR Lyr variability. We also determine the value of the extinction-insensitive parameter V_{V-I} for RR Lyr stars in fields with different galactic longitude l and compare with values of V_{V-I} calculated for red clump stars by Stanek et al. (1994). The observed and free from interstellar extinction mean brightness and V-I color of RR Lyr stars are also presented.