The optical gravitational lensing experiment. Variable stars in globular clusters. III. RR Lyrae stars and Pop. II Cepheids in omega Centauri

We present V-band photometry for 141 variable stars from the field of omega Cen. All but one variables are either RR Lyr stars or Pop. II Cepheids. One object is a distant background RR Lyr star from the galactic halo. The presented sample includes 33 newly identified variables, mostly low amplitude RR Lyr stars. We identified also two Pop. II Cepheids with exceptionally low amplitudes of light variations A_V < 0.2 mag. The presented data may be used to study period changes of omega Cen variables and/or for Fourier decomposition of light curves. Tables 3-200 are available in electronic form only at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/Abstract.html Based on observations collected at the Las Campanas Observatory of the Carnegie Institution of Washington.