![]() Produce significant changes on the populations of blue, yellow and red At solar metallicity, the enhanced mass-loss rate models do Rate has a strong impact on the RSG lifetimes and therefore on the luminosityįunction of RSGs. Than to the mass-loss rates during that phase. The surface abundances of RSGs are much more sensitive to rotation The structure of the stars at that time change for various mass-loss ratesĭuring the red supergiant phase (RSG), and for two different initial rotation ![]() (HRD), the positions in this diagram of the pre-supernova progenitor as well as How the red supergiant lifetimes, the tracks in the Hertzsprung-Russel diagram ![]() Metallicity, the mass-loss rate and the effect of a close companion. Key parameters are the mixing processes, the The post main-sequence evolution of massive stars is very sensitive to many The new tracks supersede the previous old padova models of massive stars. Stellar systems, both in local and distant galaxies. The mass, age and metallicity grids are fully adequate to perform detailed investigations of the properties of very young Tracks with new tables of theoretical bolometric corrections, useful to compare tracks and isochrones with the observations.įor this purpose, we homogenize existing stellar atmosphere libraries of hot and cool stars (Potsdam Wolf–Rayet, atlas9 and phoenix) and we add, where needed, new atmosphere models computed with wm-basic. ![]() We also predict that the Humphreys–Davidson limit should become brighter at decreasing metallicity. We thus find that the more massive stars may suffer from substantial mass-loss even at low metallicity. Predictions of recent wind models indicating that the metallicity dependence of the mass-loss rates becomes shallower when Galactic and Large Magellanic Cloud colour–magnitude diagrams, without an ad hoc mass-loss enhancement. With this new formalizm, the models are able to reproduce the Humphreys–Davidson limit observed in the The main difference with respect to our previous models of massive stars is the adoption of a recent formalizm accountingįor the mass-loss enhancement when the ratio of the stellar to the Eddington luminosity, Γe, approaches unity. We consider a broad range of metallicities, 0.0001 ≤ Z ≤ 0.04 and initial masses up to Mini = 350 M⊙. We complement the parsec data base of stellar evolutionary tracks with new models of massive stars, from the pre-main-sequence phase to the centralĬarbon ignition. These simulations put stricter limits on the extent of overshooting convection and the efficiency of semi-convection. We present some recent results of the effects of these models on a 15 solar mass star using the stellar evolution code KEPLER. (2013), from which we developed one-dimensional models. (2002) and the incompressible simulations of semi- convection by Wood et al. We also discuss compressible simulations of overshooting convection by Brummell et al. We developed a semi-analytic formulation of the thermal and compositional transport of this process, which has been tested by other groups and implemented into MESA and the Toulouse– Geneva Evolution code. We discuss our incompressible numerical simulations of one such process, thermohaline convection. These processes have been invoked through phenomenological models in order to explain away many issues in stellar evolution, such as the blue-red supergiant ratio problem and the progenitor problem of SN 1987A. Minor mixing processes-any fluid processes that mix material or transport heat other than convection or other large-scale flows-play a critical role in stellar evolution.
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