Evaluating GAIA performances on eclipsing binaries. III. Orbits and stellar parameters for UW 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 H P photometry with 8480–8740 A ground-based spectroscopy, simulating the photometric + spectroscopic observations that the GAIA mission will obtain. Tycho B T and V T 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.