TOWARDS THE CALIBRATION OF CLUSTER COLOR-MAGNITUDE DIAGRAMS

We have modelled photometric and RV observations of eclipsing binaries to calibrate observational CMDs (in the sense that the distance and r eddening are extracted) and their fitted isochrones. The work involves both detached binaries, for which mass conservation is assumed, and c ontact systems, which are studied as potential standard candles. We ha ve also analysed field delta Scuti stars and their analogues in cluste rs. The treatment of nonsolar metallicities is critical for both studi es. The work on the pulsating stars entails an improved method of asse ssing the uncertainty in the Wesselink radius and thus in luminosity.