Related papers: Stellar evolution and the 'O-rich AGB sequence'
Non-variable OH/IR stars are thought to have just left the asymptotic giant branch (AGB) phase. In this conventional picture, they must still show strong circumstellar extinction caused by the dust ejected during the AGB phase, and the…
Mass loss dominates the stellar evolution on the Asymptotic Giant Branch. The phase of highest mass-loss occurs during the last 1--10\% of the AGB and includes the so-called Miras and OH/IR stars. In this review I will discuss the…
Dynamical stellar-evolution modeling through the AGB phase reveals that radial pulsations with very fast-growing amplitudes develop if the luminosity to mass ratio of stars with tenuous envelopes exceeds a critical limit. An instability…
We have investigated the infrared properties of a sample of objects with IRAS colors typical of planetary nebulae. The selected objects have not yet evolved to the planetary nebula stage since they have no detectable radio continuum…
The DENIS/ISOGAL near/mid-IR survey of the Milky Way for the first time probes stellar populations in the innermost obscured regions of our galaxy. Ages, metallicities and extinction-corrected luminosities are derived for these stars…
The AKARI and Spitzer satellites provided an unique opportunity to observe a variety of stars, which are considered as departing from the Asymptotic Giant Branch (AGB) and have started their post-AGB evolution recently. Most of these stars…
AGB stars are ideal IR targets because they are cool and bright. Most of them escaped detection in optical or shallow IR surveys in the eighties contributing to the puzzling missing number of AGB stars with respect to theoretical…
Ultraluminous infrared galaxies (ULIRGs) have several types according to dominance of starburst or AGN component. We made stellar population analysis for a sample of 160 ULIRGs to study the evolution of ULIRGs. We found that the dominance…
We investigate the evolution of the star formation rate in the early Galaxy using beryllium and oxygen abundances in metal poor stars. Specifically, we show that stars belonging to two previously identified kinematical classes (the…
We present ISO LWS observations of the proto-planetary nebula CRL 618, a star evolving very fast to the planetary nebula stage. In addition to the lines of 12CO, 13CO, HCN and HNC, we report on the detection of H2O and OH emission together…
Aims: We investigate the change in the surface abundance of $^{12}$C during the evolution along the AGB, aiming to constrain third dredge-up models. Methods: High-resolution, near-infrared spectra of a sample of AGB stars in the LMC cluster…
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…
We study the chemical abundances of a wide sample of 142 Galactic planetary nebulae (PNe) with good quality observations, for which the abundances have been derived more or less homogeneously, thus allowing a reasonable comparison with…
We discuss the relationship between rest-frame color and optical luminosity for X-ray sources in the range 0.6<z<1.4 selected from the Chandra survey of the Extended Groth Strip (EGS). These objects are almost exclusively active galactic…
From an analysis of absorption lines in the high resolution spectra we have derived the radial velocities, stellar parameters (Teff, gravity, wind-strength parameter logQ and projected rotational velocity) and abundances (C, N, O, and Si )…
(abbreviated) Measuring the surface abundances of AGB stars is an important tool for studying the effects of nucleosynthesis and mixing in the interior of low- to intermediate mass stars during their final evolutionary phases. The…
A CO\,2-1 line survey is performed toward a sample of 58 high Galactic latitude post-AGB (pAGB) stars. To complement the observations, a compilation of literature CO\,2-1 line data of known pAGB stars is done. After combining the datasets,…
We present the main results derived from a chemical analysis carried out on a large sample of galactic O-rich AGB stars using high resolution optical spectroscopy (R~40,000-50,000) with the intention of studying their lithium abundances…
We present AKARI/IRC and Spitzer/IRS observations of a selected sample of galactic IRAS sources considered to be heavily obscured AGB/post-AGB stars based on their characteristic IRAS colours. All of them are completely invisible in the…
AGB phases mark the end of the evolution for Low- and Intermediate-Mass Stars. Our understanding of the mechanisms through which they eject the envelope and our assessment of their contribution to the chemical evolution of Galaxies are…