Related papers: HST Snapshot Survey of Post-AGB Objects
We report results of a program to image the extended circumstellar envelopes of asymptotic giant branch (AGB) stars in dust-scattered Galactic light. The goal is to characterize the shapes of the envelopes to probe the mass-loss geometry…
There is a class of binary post-asymptotic giant branch (post-AGB) stars that exhibit remarkable near-infrared (NIR) excess. These stars are surrounded by disks with Keplerian or quasi-Keplerian dynamics and outflows composed of gas…
Second-generation circumbinary discs around evolved binary stars, such as post-Asymptotic Giant Branch (post-AGB) binaries, provide insights into poorly understood mechanisms of dust processing and disc evolution across diverse stellar…
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…
S-type AGB stars are thought to be in the transitional phase between M-type and C-type AGB stars. Because of their peculiar chemical composition, one may expect a strong influence of the stellar C/O ratio on the molecular chemistry and the…
The presence of AGB stars in clusters provides key constraints for stellar models, as has been demonstrated with historical data from the Magellanic Clouds. In this work, we look for candidate AGB stars in M31 star clusters from the…
We present the initial results of a study of globular clusters in M31, using the Faint Object Camera (FOC) on the Hubble Space Telescope (HST). The sample of objects consists of 13 clusters spanning a range of properties. Three inde-…
We study the formation of multiple populations in globular clusters (GC), under the hypothesis that stars in the second generation formed from the winds of intermediate-mass stars, ejected during the asymptotic giant branch (AGB) phase,…
The study of post asymptotic giant branch (post-AGB) stars is a valuable tool to study still poorly known aspects of the evolution of the stars through the AGB. This is due to the accurate determination of their surface chemical composition…
With the wavelength coverage, sensitivity, and high spatial resolution of JWST, it is now possible to peer through the dust attenuation to probe the rest-frame near infrared (NIR) and stellar structures of extremely dusty galaxies at cosmic…
We investigate the evolution of oxygen- and carbon-rich AGB stars, post-AGB objects, and planetary nebulae using data collected mainly from the MSX catalogue. Magnitudes and colour indices are compared with those calculated from a grid of…
We present results of a survey of post-asymptotic giant branch stars (post-AGBs) at high galactic latitude. To date, few post-AGB stars are known throughout the Galaxy and the number of known members of the older populations like the…
Aims. In a first study, we characterised the properties of the gas component in the circumstellar envelopes surrounding a sample of 29 AGB stars with UV excesses. Now we intend to complement this information with an analysis of the dust…
We have carried out a search for optically visible post-AGB candidates in the Small Magellanic Cloud (SMC). We used mid-IR observations from the Spitzer Space Telescope to select optically visible candidates with a mid-IR excess. We…
In a previous paper we compared the SEDs of a sample of 808 K+A galaxies from the FUV to the MIR to the predictions of the spectrum synthesis models explicitly using AGB components. Here we use the new AGB-light models from C. Maraston…
There is a class of binary post-AGB stars (binary system including a post-AGB star) that are surrounded by Keplerian disks and outflows resulting from gas escaping from the disk. To date, there are seven sources that have been studied in…
The search for binarity in AGB stars is of critical importance for our understanding of how planetary nebulae acquire the dazzling variety of aspherical shapes which characterises this class. However, detecting binary companions in such…
Despite of numerous efforts, the stage from Asymptotic Giant Branch (AGB) to Planetary Nebulae (PN) is a poorly understood phase of stellar evolution. We have therefore carried out interferometric (VLA) observations of a sample of hot…
In this work we present the results of a systematic search for diffuse bands (DBs, hereafter) in the circumstellar envelopes of a carefully selected sample of post-AGB stars. We concentrated on the analysis of 9 of the DBs most commonly…
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…