1999BaltA...8..309F

Accurate stellar distances - as can be provided only by space astrometry - are necessary for the determination of accurate stellar fundamental parameters (in particular luminosity and mass) of single and non-eclipsing binary stars. These same parameters are needed, together with the oscillation frequencies determined by asteroseismologic observations, to provide stringent tests of stellar structure and evolution models. The impact on stellar structure studies of the upcoming generation of space astrometric and asteroseismological missions (in particular GAIA, currently under study at the European Space Agency) is discussed.