SIMBAD references

Newly published theoretical grids of stellar models are used to evaluate masses and ages of 21 stars with proven λ Bootis characteristics. Basic input parameters as effective temperature and luminosity for each star are calculated from their uvbyβ indices. Masses thus estimated are in the range of 1.6-2.7 solar masses, the evolutionary ages are between 10⁷ and 10⁹ years. In terms of stellar evolution, most of the studied λ Bootis stars are in the middle of their main sequence evolution. Only a few of them are young enough to fulfill the requirements of the "diffusion/accretion" model. Masses and ages of the examined stars are compared with already published [Fe/H] data. Iron is less deficient in more massive λ Bootis stars. There is no evidence for significant change in the chemical composition of considered λ Bootis type stars during their evolution on the main sequence.