相关论文: The post-AGB evolution of AGB mass loss variations

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…

The concept of overshoot has already been considered for numerous cases in stellar evolution calculations. We explore the consequences of overshoot at the convection zone which forms during the He-flash (thermal pulse) in AGB stars. We find…

We investigate the main physical properties of low-metallicity Asymptotic Giant Branch stars, with the aim of quantifying the uncertainties that presently affect the predicted chemical yields of these stars, associated to mass loss and…

More than half of the dust and heavy element enrichment in galaxies originates from the winds and outflows of evolved, low-to-intermediate mass stars on the asymptotic giant branch (AGB). However, numerous details of the physics of…

This paper reports the results of the numerical study of the formation of aspherical Planetary Nebulae through the Generalised Interacting Winds Model, taking into account the effects caused by the evolving central star and fast wind. The…

We study the Galactic distribution of ~10,000 Asymptotic Giant Branch (AGB) stars selected by IRAS colors and variability index. The distance to each star is estimated by assuming a narrow luminosity function and a model-derived bolometric…

The onset of the asymmetry of planetary nebulae (PNe) is expected to occur during the late Asymptotic Giant Branch (AGB) and early post-AGB phases of low- and intermediate-mass stars. Among all post-AGB objects, the most heavily obscured…

Observations of planetary nebulae (PNe) by Sterling, Dinerstein and Bowers have revealed abundances in the neutron-capture element Germanium (Ge) from solar to factors of 3 -- 10 above solar. The enhanced Ge is an indication that the…

Infrared Space Observatory (ISO) observations have shown that O-rich Asymptotic Giant Branch (AGB) stars exhibit crystalline silicate features in their spectra only if their mass-loss rate is higher than a certain threshold value. Usually,…

Asymptotic giant branch (AGB) stars are known to lose a significant amount of mass by a stellar wind, which controls the remainder of their stellar lifetime. High angular-resolution observations show that the winds of these cool stars…

The winds observed around asymptotic giant branch (AGB) stars are generally attributed to radiation pressure on dust, which is formed in the extended dynamical atmospheres of these pulsating, strongly convective stars. Current…

Gamma-ray bursts (GRBs) are fascinating extragalactic objects. They represent a fantastic opportunity to investigate unique properties not exhibited in other sources. Multi-wavelength afterglow observations from some short- and…

We present recent progress in our understanding of the physical interaction mechanisms at work in evolved binaries of low-to-intermediate initial mass, which are surrounded by a stable disc of gas and dust. These systems are known as…

Observational evidence for strong magnetic fields throughout the envelopes of evolved stars is increasing. Many of the instruments coming on line in the near-future will be able to make further contributions to this field. Specifically,…

Low- and intermediate-mass stars evolve through the asymptotic giant branch (AGB), when an efficient mass-loss process removes a significant fraction of their initial mass. A substantial increase in the mass-loss rate at the end of the AGB…

We address the fundamental question of matching the rest-frame K-band luminosity function (LF) of galaxies over the Hubble time using semi-analytic models, after modification of the stellar population modelling. We include the Maraston…

We present the results of mid-resolution spectroscopy in the LiI 6708 AA spectral region of Asymptotic Giant Branch (AGB) stars belonging to young open clusters of the Large Magellanic Cloud. Most stars belong to the clusters NGC 1866 and…

We show that the inclusion of axion emission during stellar evolution introduces important changes into the evolutionary behaviour of AGB stars. The mass of the resulting C/O white dwarf is much lower than the equivalent obtained from…

I propose a mechanism for axisymmetrical mass loss on the asymptotic giant branch, that may account for the axially symmetric structure of elliptical planetary nebulae. The proposed model operates for slowly rotating AGB stars, having…

Models describing dust-driven winds are important for understanding the physical mechanism and properties of mass loss on the asymptotic giant branch. These models are becoming increasingly realistic with more detailed physics included, but…