Consequences of Hipparcos parallaxes for stellar evolutionary models. Three Hyades binaries: V818 Tauri, 51 Tauri, and ${\theta }^2$ Tauri

E. Lastennet, D. Valls-Gabaud, T. Lejeune +1

Three binary systems in the Hyades open cluster (51 Tau, V818 Tau, and ${\theta }^2$ Tau}, with known metallicity and good Johnson photometric data are used to test the validity of three i…