Related papers: Do zero metal intermediate mass stars experience t…
We present a set of models of AGB stars with initial mass larger than 5 Mo as obtained with the FRANEC code. It includes models of Z=0.02 and Z=0.001, with and without mass loss.
Low and intermediate mass stars with super solar metallicities comprise a known portion of the universe. Yet yields for asymptotic giant branch (AGB) stars with metallicities greater than $Z=0.04$ do not exist in the literature. This…
The literature is rich in analysis and results related to thermally pulsing-asymptotic giant branch (TP-AGB) stars, but the problem of the instabilities that arise and cause the divergence of models during the late stages of their evolution…
AGB stars have long been held responsible for the important star-to-star variations in light elements observed in Galactic globular clusters. We analyse the main impacts of a first generation of rotating intermediate-mass stars on the…
We present theoretical evolutionary models for Z=0 stars in the mass range 4< M/Mo <8 from the pre-main sequence up to the AGB phase. Contrary to previous calculations we found that these stars develop normal thermal pulses and third…
We have extended our published set of low mass AGB stellar models to lower metallicity. Different mass loss rates have been explored. Interpolation formulae for luminosity, effective temperature, core mass, mass of dredge up material and…
The main component of the s process is produced by low mass stars (between 1.5 and 3 Mo), when they climb for the second time the red giant branch and experience a series of He shell flashes called thermal pulses. During the relatively long…
The 19F production during the first dozen thermal pulses of AGB stars with (M=3,Z=0.02), (M=6,Z=0.02) and (M=3,Z=0.001) is investigated on grounds of detailed stellar models and of revised rates for 15N(a,g)19F and 18O(a,g)22Ne. These…
Stars in the narrow mass range of about 2.5 and 3.5 solar masses can develop a thermally unstable He-burning shell during its ignition phase. We study, from the point of view secular stability theory, these so called thermal micropulses and…
High dispersion near-infrared spectra have been taken of seven highly-evolved, variable, intermediate-mass (4-6 Msun) AGB stars in the LMC and SMC in order to look for C, N and O variations that are expected to arise from third dredge-up…
The thermally pulsing phase on the asymptotic giant branch (TP-AGB) is the last nuclear burning phase experienced by most of low and intermediate mass stars. During this phase, the outer chemical stratification above the C/O core of the…
We present a new set of models for intermediate mass AGB stars (4.0, 5.0 and, 6.0 Msun) at different metallicities (-2.15<=Fe/H]<=+0.15). This integrates the existing set of models for low mass AGB stars (1.3<=M/M<=3.0) already included in…
Abridged. We aim to better characterise the evolution and fates, and determine updated nucleosynthetic yields of intermediate-mass stars between primordial and EMP metallicity (Z=1e-10, 1e-8, 1e-7, 1e-6 and 1e-5). We also probed…
We present results of the evolution of AGB stars of 3M_sol and 5M_sol with solar metallicity calculated with the Eggleton stellar evolution code (STARS), which has a fully implicit and simultaneous method for solving for the stellar…
Before reaching their quiescent terminal white-dwarf cooling branch, some low-mass helium-core white dwarf stellar models experience a number of nuclear flashes which greatly reduce their hydrogen envelopes. Just before the occurrence of…
Recent advances in constructing stellar evolution models of hydrogen-deficient post-asymptotic giant branch (AGB) stars are presented. Hydrogen-deficiency can originate from mixing and subsequent convective burning of protons in the deeper…
Time-dependent nuclear network calculations at constant temperature show that for zero-metal stars >= 20 Msun (i) beta-decay reactions and (ii) the 13N(p,gamma)14O reaction must be included. It is also shown that the nuclear timescale in…
We present full stellar evolution and parametric models of the surface abundance evolution of O16, Ne22, Na23 and the magnesium isotopes in an extremely metal-poor intermediate mass star M_ZAMS=5M_sun, Z=0.0001. O16 and Ne22 are injected…
Spectral analyses of H-deficient post-AGB stars have shown that a small group of four extremely hot objects exists which have almost pure He absorption-line spectra in the optical. These are classified as O(He) stars. For their evolution…
An analysis of high-resolution near-infrared spectra of a sample of 45 asymptotic giant branch (AGB) stars towards the Galactic bulge is presented. The sample consists of two subsamples, a larger one in the inner and intermediate bulge, and…