Fourier coefficients of OGLE variables. IV. RR Lyr stars in omega Cen and towards 47 Tuc

Fourier coefficients for RR Lyr stars found by the OGLE survey in omega Cen and in the direction of 47 Tuc are presented. A total of 180 light curves were examined. Physical parameters for the stars including mass, luminosity , effective temperature and metallicity were derived using theoretical rela tions based upon the Fourier coefficients. The well known metallicity varia tion is seen in the w Cen RR Lyr variables. The distance modulus to w Cen i s estimated to be (m -M) = 13.73 +/- 0.07 mag, while the RR Lyr stars seen in the direction of 47 Tuc are located in the Small Magellanic Cloud, and h ave an estimated distance modulus of (m - M) = 18.78 +/- 0.08 mag.