W~UMa-type Systems in the Central Baade Window Discovered in the OGLE Experiment

Abstract

77 W~UMa-type systems to $I=18$ mag in one of the 21 fields of OGLE have been assessed in terms of utility for extraction of astrophysical information from time-independent data such as colors, periods, maximum magnitudes, and variability amplitudes in the final global OGLE catalog which will contain $>1000$ contact binaries. A subset of systems with absolute magnitudes $M_I < 3$ permits mapping of stellar distribution towards the Galactic Bulge to about 6~kpc from us, with indications that the reddening $E_{V-I} > 0.6$.Comment: text and 5 figures in PS format, packed with uufiles, submitted to ApJLet