Alpha-process elements in the Galaxy: a possible GAIA contribution
  The sensitivity of stellar spectra to alpha/Fe abundance changes is investigated with the aim to be detected photometricly and employed for scientific goals of the GAIA mission. A grid of plane parallel, line blanketed, flux constant, LTE model atmospheres with different [alpha/Fe] ratios was calculated. As a first step, the modelled stellar energy fluxes for solar-type stars and giants were computed and intercompared. The spectral sensitivity talpha/Fe abundance changes is noticeable and has to be taken into account when selecting photometric filters for GAIA. The Ca II H and K lines and Mg I b triplet are the most sensitive direct indicators of alpha/Fe abundance changes. 
Grazina Tautvaisiene (1) and Bengt Edvardsson (2) ((1)Institute of   Theoretical Physics and Astronomy, Vilnius, Lithuania, ...