Related papers: Dynamic model atmospheres of cool giants
A new semi-analytical model of a star evolving in a tidal field is proposed. The model is a generalization of the so-called 'affine' stellar model. In our model the star is composed of elliptical shells with different parameters and…
The characterization of exoplanetary atmospheres has come of age in the last decade, as astronomical techniques now allow for albedos, chemical abundances, temperature profiles and maps, rotation periods and even wind speeds to be measured.…
We present here a study of the Infrared properties of Asymptotic Giant Branch stars (hereafter AGB) based on existing databases, mainly from space-borne experiments. Preliminary results about C and S stars are discussed, focusing on the…
Recent numerical simulations of the interstellar medium driven by energy input from supernovae and stellar winds indicate that HI clouds can be formed by compression in shock waves and colliding turbulent streams without any help from…
The outflows of asymptotic giant branch (AGB) stars are rich astrochemical laboratories, hosting different chemical regimes: from non-equilibrium chemistry close to the star, to dust formation further out, and finally photochemistry in the…
We examine the envelope properties of asymptotic giant branch (AGB) stars as they evolve on the upper AGB and during the early post-AGB phase. Due to the high mass loss rate, the envelope mass decreases by more than an order of magnitude.…
This work is part of an ongoing effort aiming at identifying the actual wind-drivers among the dust species observed in circumstellar envelopes. In particular, we focus on the interplay between a strong stellar radiation field and the dust…
Massive stars drive strong winds that impact the surrounding interstellar medium, producing parsec-scale bubbles for isolated stars and superbubbles around young clusters. These bubbles can be observed across the electromagnetic spectrum,…
Post-AGB stars evolve on a very fast track and hence not many are known. Their spectral properties make them, in principle, ideal objects to test our theories on the late phases of stellar evolution. This has, however, proven much more…
Asymptotic giant branch (AGB) stars play a key role in the enrichment of galaxies with heavy elements. Due to their large amplitude variability, the measurement of elemental abundances is a highly challenging task that has not been solved…
The physics of compact objects is one of the very actively developing branches of theoretical investigations, since the careful analysis of different models for the internal structure of these objects, their evolutionary characteristics and…
We present a review of AGB star evolution, with emphasis on the nucleosynthesis occurring in these stars. In particular, we discuss hot and cool bottom burning, observational constraints, and analysis of meteoritic grains. This paper was…
Numerical models of the dynamical interstellar medium show that interactions between structures such as supernova remnants and superbubbles are more important than the structures themselves in determining the behavior of the ISM. I review…
The evolution of galaxies is driven by the birth and death of stars. AGB stars are at the end points of their evolution and therefore their luminosities directly reflect their birth mass; this enables us to reconstruct the star formation…
We present Very Low Mass stellar models as computed including non-grey model atmospheres for selected assumptions about the star metallicities. The role of atmospheres is discussed and the models are compared with models based on the…
We present results of an analysis of the optical spectrum of the post-AGB star HD56126 (IRAS 07134+1005) based on observations made with the echelle spectrographs of the 6-m telescope with spectral resolutions of R=25000 and 60000 at…
A popular self--enrichment scenario for the formation of globular clusters assumes that the abundance anomalies shown by the stars in many clusters are due to a second stage of star formation occurring from the matter lost by the winds of…
Radiative acceleration of newly-formed dust grains and transfer of momentum from the dust to the gas plays an important role for driving winds of AGB stars. Therefore a detailed description of the interaction of gas and dust is a…
The recent years have brought great advances in our knowledge of magnetic fields in cool giant and supergiant stars. For example, starspots have been directly imaged on the surface of an active giant star using optical interferometry, and…
Convection and turbulence in stellar atmospheres have a significant effect on the emergent flux from late-type stars. The theoretical advancements in convection modelling over recent years have proved challenging for the observers to obtain…