Globular Cluster Distances and Physical Properties from Double- and   Fundamental Mode Variables
  We briefly describe a method of obtaining relative intrinsic stellar parameters, such as absolute magnitudes and colors from the light curves of fundamental mode RR Lyrae (RRab) stars. Absolute stellar parameters of double-mode variables (Cepheids and RR Lyrae stars) can be computed from their periods and intrinsic colors combined with stellar atmosphere and pulsation models. By using these two methods, one can determine, e.g., the distance of any RRab star, assuming that accurate multicolor photometry is available. By applying this and a related method for computing metallicity, we derive distance, reddening and metallicity distribution for the RRab stars of omega Cen. 
G. Kov\'acs