EVOLUTIONARY STELLAR MODELS USING ROGERS AND IGLESIAS OPACITIES, WITH PARTICULAR ATTENTION TO INTERNAL STRUCTURE CONSTANTS

New stellar evolutionary models, including internal structure constants, are presented in this paper making use of the most recent input physics in order to extend our previous studies on this subject. The new opacities (Anders-Grevesse mixture) recently obtained at Lawrence Livermore Laboratory by Rogers & Iglesias have been introduced and for the lower temperatures we have adopted recent computations by Alexander. The main impact of these improvements were the changes of the solar helium content and mixing-length parameter. The adopted initial chemical compositions are (Y, Z) = (0.267, 0.01); (0.280, 0.02); (0,294, 0.02) and (0.321, 0.03) in order to cover the range of metallic abundances generally found in double-lined eclipsing binary stars. The grids cover a mass range from 1 to 40 M. and were computed from the ZAMS up to the first phases of carbon ignition. Core overshooting and mass loss were taked into account though standard models are also available on request. The new models show a general tendency to be cooler and more centrally concentrated in mass than our previous computations for the typical masses where apsidal motion is observed. Concerning the stellar interior this tendency is a good indication that the revised opacity calculations may help, together with other improvements in the adopted physics of the models, to explain the still remaining discrepancies between observed apsidal motion rates and theoretical predictions.