Three binary systems in the Hyades open cluster, with known metallicity and good Johnson photometric data are used to test the validity of three independent sets of stellar evolutionary tracks. A statistical method is described and applied to the colour-magnitude diagram of the six selected components, giving rise to $\chi^2$-contours in the age-metallicity plane. The effects of the Hipparcos parallaxes on these confidence regions are studied for these binaries through a comparison with very accurate but older orbital parallaxes. Independent simultaneous age-metallicity estimates are given and compared with observational constraints (see Lastennet et al. 1999, astro-ph/9905273, for more details).
Comment: 4 pages, to appear in the PASP Conference Proceedings series of the Workshop "Spectrophotometric dating of stars and galaxies", Annapolis, Maryland (U.S.A.), eds. I. Hubeny, S. Heap, and R. Cornett