A. Bressan et al., EVOLUTIONARY SEQUENCES OF STELLAR MODELS WITH NEW RADIATIVE OPACITIES.2. Z = 0.02, Astronomy & Astrophysics. Supplement series, 100(3), 1993, pp. 647-664
We present a large grid of stellar models computed with the most recen
t radiative opacities by Iglesias et al. (1992). The chemical composit
ion, typical of the solar vicinity, is X = 0.700, Y = 0.28, and Z = 0.
020. The evolutionary tracks have initial masses in the range 0.6 M. t
o 120 M. and extend from the zero age main sequence (ZAMS) to the begi
nning of the thermally pulsing regime of the asymptotic giant branch p
hase (TPAGB) for low and intermediate mass stars, and to the central C
-ignition for higher masses. The computations are performed adopting a
moderate non local overshoot from convective regions. Low and interme
diate mass stars calculated at constant mass because mass loss during
the red giant (RGB) and asymptotic giant branch (AGB) phases can be ea
sily included following the standard analytical procedure, while massi
ve stars (M greater-than-or-equal-to 12 M.) are evolved in presence of
mass loss by stellar winds. The remaining physical input of the stell
ar models, i.e. nuclear reaction rates, nucleosynthesis network, neutr
ino energy losses, boundary conditions in the outer layers etc., is as
in Alongi et al. (1992), but for the mixing length parameter in the o
utermost super-adiabatic convection. With the new opacities, the lumin
osity and effective temperature of the Sun are matched by our model st
ar with the age of 4.7 10(9) yr by adopting a mixing length parameter
alpha = 1.63 instead of 1.5 as found by Alongi et al. (1992) with the
Los Alamos opacity by Huebner et al. (1977). For purposes of compariso
n, two additional samples of models are presented with different detai
l. The first sample contains models calculated with the same physical
input (chemical composition, opacity, etc) as above but the classical
mixing scheme (no overshoot and semiconvection during the core He-burn
ing phase). The models of the second group, whose properties are preen
ted here limited to the lifetimes of the major evolutionary phases, ar
e calculated with the same chemical composition, convective overshoot,
and the opacity by Huebner et al. (1977). The results of all the mode
ls are given in extensive tables. In addition to this, we shortly disc
uss some general properties of the models such as the evolutionary pat
h in the Hertzsprung-Russell diagram (HRD), the lifetimes of the vario
us phases, and the variation of the surface abundance induced by exter
nal convection and mass loss by stellar wind.