Theoretical isochrones for globular clusters with predicted Thuan-Gunn photometry

Synthetic spectra have been computed for a grid of model atmospheres of cool dwarf stars. These spectra have been used to compute the colors and g-magnitudes of the models on the Thuan-Gunn uvgr system. The calculations have been used to study the properties of the uvgr system, by determining reddening coefficients, extinction corrections, and transformation equations to other color systems. The uvgr color-temperature relations have been used to convert stellar evolutionary sequences and isochrones, calculated for metallicities and ages appropriate to the Galactic globular clusters, from the (L, Teff)-plane to variety of Thuan-Gunn observational planes. The isochrones, which have been extended down to M(g) ≡ 8, are compared with recent CCD data.