Related papers: AGB Stars: What Should Be Done ?
It is well known that thermally pulsing Asymptotic Giant Branch stars with low mass play a relevant role in the chemical evolution. They have synthesized about 30% of the galactic carbon and provide an important contribution to the…
Dust is formed in the expanding atmosphere during late stages of stellar evolution. Dust influences the dynamics and thermodynamics of the stellar atmosphere by its opacity. The dust opacity depends both on the optical properties of the…
Lithium and zirconium abundances (the latter taken as representative for s-process enrichment) are determined for a large sample of massive Galactic O-rich AGB stars, for which high resolution optical spectroscopy has been obtained…
Structural and chemical changes during the AGB and post-AGB evolution are discussed with respect to two recent observational and theoretical findings. On the one hand, high-resolution infrared observations revealed details of the dynamical…
Spectral analysis by means of Non-LTE model-atmosphere techniques has arrived at a high level of sophistication: fully line-blanketed model atmospheres which consider opacities of all elements from H to Ni allow the reliable determination…
We present a summary of current research on planetary nebulae and their central stars, and related subjects such as atomic processes in ionized nebulae, AGB and post-AGB evolution. Future advances are discussed that will be essential to…
We study the asymptotic giant branch (AGB) evolution of stars with masses between $1~M_{\odot} - 8.5~M_{\odot}$. We focus on stars with a solar chemical composition, which allows us to interpret evolved stars in the Galaxy. We present a…
Many nucleosynthesis and mixing processes of low-mass stars as they evolve from the Main Sequence to the thermal-pulse Asymptotic Giant Branch phase (TP-AGB) are well understood (although of course important physics components, e.g.…
The envelope of thermally pulsing AGB stars undergoing periodic third dredge-up episodes is enriched in both light and heavy elements, the ashes of a complex internal nucleosynthesis involving p, alpha and n captures over hundreds of stable…
The goal of this study is to reconstruct the evolution and the dust formation processes during the final AGB phases of a sample of carbon-rich, post-AGB Galactic stars, with particular attention to the determination of the past mass-loss…
The evolution of AGB stars is notoriously complex. The confrontation of AGB population models with observed stellar populations is a useful alternative to the detailed study of individual stars in efforts to converge towards a reliable…
Barium stars are extrinsic Asymptotic Giant Branch (AGB) stars. They present the s-enhancement characteristic for AGB and post-AGB stars, but are in an earlier evolutionary stage (main sequence dwarfs, subgiants, red giants). They are…
The study of the evolutionary properties of Asymptotic Giant Branch stars still presents unresolved topics. Progress in the theoretical understanding of their evolution is hampered by the difficulty to empirically explain key physical…
Among presolar materials recovered in meteorites, abundant SiC and Al$_{2}$O$_{3}$ grains of AGB origins were found. They showed records of C, N, O, $^{26}$Al and s-element isotopic ratios that proved invaluable in constraining the…
We discuss the basic physical model and the relevant processes responsible for creating and shaping planetary nebulae out of a cool AGB wind envelope. We show that a hydrodynamical treatment along the upper AGB leads quite naturally to more…
I discuss the relationship between mass loss and nucleosynthesis on the Asymptotic Giant Branch (AGB). Because of thermal pulses and possibly other mixing processes, products of nucleosynthesis can be brought to the surface of AGB stars,…
In this introduction to the Third Congress of Vienna on AGB stars I first try to highlight why it is so hard to cope with the AGB evolutionary phase. This phase is indeed dominated by three main physical processes concerning bulk motions of…
Asymptotic giant branch (AGB) stars can experience proton ingestion events (PIEs), leading to a rich nucleosynthesis. During a PIE, the intermediate neutron capture process (i-process) develops, leading to the production of trans-iron…
I discuss recent new models of post-Asymptotic Giant Branch stellar evolution. These models aim to clarify the evolutionary origin and status of a variety of hydrogen-deficient post-AGB stars such as central stars of planetary nebulae of…
Cool giant stars are highly dynamical objects, and complex micro-physical processes play an important role in their extended atmospheres and winds. The interpretation of observations, and in particular of high-resolution IR spectra,…