Evaluating GAIA performances on ecplipsing binaries. III. Orbits and stellar parameters forUW LMi, V432 Aur and CN Lyn

The orbits and physical parameters of three detached F and G-type eclipsing binaries have been derived combining Hipparcos HP photometry with 8480–8740 Å ground-based spectroscopy, simulating the photometric + spectroscopic observations that the GAIA mission will obtain. Tycho BT and VT light curves are too noisy to be modeled for the three targets, and only mean Tycho colors are retained to constrain the temperature. No previous combined photometric+spectroscopic solution exists in the literature for any of the three targets. Quite remarkably, CN Lyn turned out to be an equal-masses F5 triple system. Distances from the orbital solutions agree within the astrometric error with the Hipparcos parallaxes.