Resumen

PENA, J. H. et al. Physical parameters of seven field RR Lyrae Stars in bootes. Rev. mex. astron. astrofis [online]. 2009, vol.45, n.2, pp.191-203. ISSN 0185-1101.

Strömgren uvby - β photometry is reported for the RR Lyrae stars AE, RS, ST, TV, TW, UU, and XX in Bootes. The physical parameters M/M log(L/L), MV, log T_eff and [Fe/H], have been estimated from the Fourier decomposition of the light curves and the empirical calibrations developed for this type of stars. The obtained [Fe/H] values are compared with those calculated from the ΔS index for some sample stars. It was found that reddening in the zone is negligible compared to that shown by several objects in the same sky zone. From that, distance to the stars was calculated. The variation of the unreddened indexes (b-y)₀ and c₁ along the pulsational cycle allows the direct comparison with the theoretical grids and, hence, an independent determination of T_eff and log g.

Palabras llave : stars: variables: RR Lyrae; techniques: photometric.