THEORETICAL ISOCHRONES FROM MODELS WITH NEW RADIATIVE OPACITIES

In this paper we present large grids of theoretical isochrones for the initial chemical compositions [Z=0.0004, Y=0.23], [Z=0.004, Y=0.24], [Z=0.008, Y=0.25], [Z=0.02, Y=0.28], and [Z= 0.05, Y=0.352] and ages i n the range 4 10(6) yr to 16 10(9) yr. These isochrones are derived fr om stellar models computed with the most recent radiative opacities by Iglesias et al. (1992). In addition to this we present another set wi th chemical composition [Z=0.001, Y=0.231 based on models calculated w ith the radiative opacities by Huebner et al. (1977). All the stellar models are followed from the zero age main sequence (ZAMS) to the cent ral carbon ignition for massive stars or to the beginning of the therm ally pulsing regime of the asymptotic giant branch phase (TP-AGB) for low and intermediate mass stars. For each isochrone, we give the curre nt mass, effective temperatures, bolometric and visual magnitudes, (U - B), (B - V), (V - R), (V - I), (V - J), (V - H), and (V - K) colors, and the luminosity function for the case of the Salpeter law. In addi tion to this, integrated magnitudes and colors at several characterist ic points are also presented together with the mass of the remnant sta r when appropriate. The main characteristic that makes this set of iso chrones very valuable is based on their extension in mass and chemical composition, besides the calculation of late stages of evolution, bey ond the red giant tip till the white dwarf stage after the planetary n ebula phase.