  Based on spectrophotometric observations from the Guillermo Haro Observatory
(Cananea, Mexico), a study of the spectral properties of the complete sample of
24 blue straggler stars (BSs) in the old Galactic open cluster M67 (NGC 2682)
is presented. All spectra, calibrated using spectral standards, were
recalibrated by means of photometric magnitudes in the
Beijing-Arizona-Taipei-Connecticut system, which includes fluxes in 11 bands
covering ~3500-10000 A. The set of parameters was obtained using two
complementary approaches that rely on a comparison of the spectra with (i) an
empirical sample of stars with well-established spectral types and (ii) a
theoretical grid of optical spectra computed at both low and high resolution.
The overall results indicate that the BSs in M67 span a wide range in Teff(~
5600 -12600 K) and surface gravities that are fully compatible with those
expected for main-sequence objects (log g = 3.5 -5.0 dex).
