We summarize the main physical assumptions and numerical procedures adopted by the FRANEC code to compute stellar models in all the evolutionary phases at hydrostatic and thermal equilibrium. An application to the Standard Solar Model is also briefly presented

The luminosities and effective temperatures, as well as the whole bolometric light curves of non‐linear convective RR Lyrae models with 0.0001 ≤Z≤ 0.006, are transformed into the Sloan Digital Sky Survey (SDSS) photometric system. The obtained ugriz light curves, mean magnitudes and colours, pulsation amplitudes and colour–colour loops are shown and analytical relations connecting pulsational to intrinsic stellar parameters, similar to the ones currently used in the Johnson–Cousins filters, are derived. Finally, the behaviour in the colour–colour planes is compared with available observations in the literature and possible systematic uncertainties affecting this comparison are discussed.

We present the results of a photometric multisite campaign on the δ Scuti Pre-Main-Sequence star IP Per. Nine telescopes have been involved in the observations, with a total of about 190 h of observations over 38 nights. Present data confirms the multiperiodic nature of this star and leads to the identification of at least nine pulsational frequencies. Comparison with the predictions of linear non-adiabatic radial pulsation models allowed us to identify only five of the nine observed frequencies, and to constrain the position of IP Per in the HR diagram. The latter is in good agreement with the empirical determination of the stellar parameters obtained by Miroshnichenko et al. (2001, A&A, 377, 854). An initial interpretation of the observed frequencies using the Aarhus non-radial pulsation code suggests that three frequencies could be associated with non-radial (l = 2) modes. Finally, we present new evolutionary and pulsation models at lower metallicity (Z = 0.008) to take into account the possibility that IP Per is metal deficient, as indicated by Miroshnichenko et al. (2001, A&A, 377, 854).

Abstract. In this paper we present a modified version of the CORS method based on a new calibration of the Surface Brightness function in the Strömgren photometric system. The method has been tested by means of synthetic light and radial velocity curves derived from nonlinear pulsation models. Detailed simulations have been performed to take into account the quality of real observed curves as well as possible shifts between photometric and radial velocity data. The method has been then applied to a sample of Galactic Cepheids with Strömgren photometry and radial velocity data to derive the radii and a new PR relation. As a result we find log R = (1.19 ± 0.09) + (0.74 ± 0.11) log P (rms = 0.07). The comparison between our result and previous estimates in the literature is satisfactory. Better results are expected from the adoption of improved model atmosphere grids.