M. Chavez, E. Bertone, J. B. Hernandez-Aguila, C. Tapia-Schiavon, J. R. Valdes and V. Chavushyan

We present a progress report on the determination of the leading atmospheric parameters of an extended sample of more than 1000 solar analogues (main sequence stars of spectral types G0-G3) in the northern hemisphere. We theoretically demonstrate the capabilities of diagnostic diagrams of line depth indices in the determination of effective temperature and surface gravity. The diagrams were constructed after analyzing all possible index-index combinations of a variety of spectral features in the wavelength region 3800-4700 angstroms, observed at a moderate spectral resolution (FWHM~2.5 angstroms). Aimed at validating the proposed technique, we applied the diagnostic diagrams to a selected sample of stars of M67 and found that, under the assumption of solar chemical composition, we obtain a set of atmospheric parameters compatible with those determined from high resolution studies. The next step is to include a third dimension (chemical composition) in the diagrams and apply the method to the full sample.