Related papers: What does a typical full-disc around a post-AGB bi…
(abridged) Debris disks around main sequence stars are produced by the erosion and evaporation of unseen parent bodies. AU Microscopii (GJ 803) is a compelling object to study in the context of disk evolution across different spectral…
We present a long-term optical spectroscopic study of the post-AGB binary system 89 Herculis, with the aim to characterize the relationship between photospheric instabilities and dynamics in the close circumstellar environment of the…
Context. With its high complexity, large size, and close distance, the ringworld around GG Tau A is an appealing case to study the formation and evolution of protoplanetary disks around multiple star systems. However, investigations with…
Aims: We aim to characterize the physical and morphological properties of the binary system AFGL 4106, composed of two evolved massive stars. Understanding its mass-loss processes and circumstellar environment offers insight into the late…
As mass-losing asymptotic giant branch (AGB) stars evolve to planetary nebulae (PNe), the mass outflow geometries transform from nearly spherical to extreme aspherical. The physical mechanisms governing this transformation are widely…
We present deep, near-infrared images of the circumbinary disk surrounding the pre-main-sequence binary star, GG Tau A, obtained with NICMOS aboard the Hubble Space Telescope. The spatially resolved proto-planetary disk scatters roughly…
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…
This review presents the latest advances in the nebular studies of post-AGB objects. Post-AGB stars are great tools to test nucleosynthesis and evolution models for stars of low and intermediate masses, and the evolution of dust in harsh…
Aim: We aim to study in detail the peculiar mineralogy and structure of the circumstellar environment of two binary post-AGB stars, EPLyr and HD52961. Both stars were selected from a larger sample of evolved disc sources observed with…
Post-common-envelope binaries (PCEBs) containing a white dwarf (WD) and a main-sequence (MS) star can constrain the physics of common envelope evolution and calibrate binary evolution models. Most PCEBs studied to date have short orbital…
We explore test particle orbits in the orbital plane of eccentric stellar binary systems, searching for ``invariant loops'': closed curves that change shape periodically as a function of binary orbital phase as the test particles in them…
We present a 3D hydrodynamics study of gravitational instabilities (GIs) in a 0.14 M$_{\odot}$ circumbinary protoplanetary disc orbiting a 1 M$_{\odot}$ star and a 0.02 M$_{\odot}$ brown dwarf companion. We examine the thermodynamical state…
We present a large set of theoretical isochrones, whose distinctive features mostly reside on the greatly improved treatment of the thermally pulsing asymptotic giant branch (TP-AGB) phase. Essentially, we have coupled the TP-AGB tracks…
The Post Asymptotic Giant Branch (AGB) phase is arguably one of the least understood phases of the evolution of low- and intermediate- mass stars. The two grids of models presently available are based on outdated micro- and macro-physics…
In the recent literature there has been some doubt as to the reliability of CO multi-transitional line observations as a mass-loss-rate estimator for AGB stars. Mass-loss rates for 10 intermediate- to high-mass-loss-rate AGB stars are…
One of the puzzling findings in the study of the chemical evolution of (post-)AGB stars is why very similar stars (in terms of metallicity, spectral type, infrared properties, etc...) show a very different photospheric composition. We aim…
HD 98800 is a young ($\sim10$ Myr old) and nearby ($\sim45$ pc) quadruple system, composed of two spectroscopic binaries orbiting around each other (AaAb and BaBb), with a gas-rich disk in polar configuration around BaBb. While the orbital…
Semi-regular (SR) variables are not a homogeneous class and their variability is often explained due to pulsations and/or binarity. This study focuses on IRAS 19135+3937, an SRd variable with an infra-red excess indicative of a dusty disc.…
The physical mechanism(s) responsible for transitioning from a spherical Asymptotic Giant Branch (AGB) star to an asymmetric post-AGB (pAGB) object is poorly understood. In particular, excess momenta in the outflows of pAGB objects suggest…
Observations of increasingly higher spatial resolution reveal the existence of asymmetries in the circumstellar envelopes of a small fraction of asymptotic giant branch (AGB) stars. Although there is no general consensus for their origin, a…