Evolutionary sequences of stellar models with semiconvection and convective overshoot. I Z=0.008

Abstract

We present two grids of evolutionary stellar models covering the phases of core H- and He-burning for stars having masses in the range 0.6 M ○ . to 100 M ○ . with composition (Y = 0.25 and Z = 0.008). The computations were performed for two different mixing schemes in the convective regions, i.e. either the classical definition of the convective core during the central H-burning phase and semiconvection during the core He-burning phase or non local overshoot from convective regions all over the major nuclear phases. All the evolutionary models were computed from the main sequence up to the stage of central carbon ignition or to the beginning of the thermally pulsing regime of the symptotic giant branch phase as appropriate to the value of the initial stellar mass