On the performance of GAIA on photometry of eclipsing binaries: The case of four near-contact and contact systems

The light curves of four eclipsing binaries (two near-contact and two contact) are analysed by means of light curve synthesis techniques to derive the geometric and photometric elements and the physical parameters of the systems. For the analysis we used ground based photometric observations and Hipparcos/Tycho photometric data, which mimic the photometric observations that should be obtained by GAIA, the approved Cornerstone 6 mission by ESA. The results are compared and the achievable precision of the basic stellar parameters derived by GAIA photometry is discussed.