Related papers: The nebula around the post-AGB star 89 Her

While the first binary post-AGB stars were serendipitously discovered, the distinct characteristics of their Spectral Energy Distribution (SED) allowed us to launch a more systematic search for binaries. We selected post-AGB objects which…

We propose that the large, radius of ~1000 AU, circumbinary rotating disks observed around some post-asymptotic giant branch (post-AGB) binary stars are formed from slow AGB wind material that is pushed back to the center of the nebula by…

Bipolarity in proto-planetary and planetary nebulae is associated with events occurring in or around their cores. Past infrared observations have revealed the presence of dusty structures around the cores, many in the form of disks.…

Adaptive optics observations in the infrared (VLT/NACO, Kervella et al. 2014) and visible (VLT/SPHERE, Kervella et al. 2015) domains revealed that the nearby AGB star L2 Pup (d=64 pc) is surrounded by a dust disk seen almost edge-on.…

We present ALMA continuum and molecular line emission maps at $\sim$1 mm of OH 231.8, a well studied bipolar nebula around an AGB star. The excellent angular resolution of our maps ($\sim$20 mas) allows us to scrutinise the central nebular…

Aims: We aim at showing that the broad-band SED characteristics of our sample of post-AGB stars are best interpreted, assuming the circumstellar dust is stored in Keplerian rotating passive discs. Methods: We present a homogeneous and…

We present our recent results on mm-wave CO observations of proto-planetary nebulae. These include high-resolution interferometric maps of various CO lines in three well known bipolar PPNe: M1-92, M2-56 and OH231.8+4.2. The global…

We report optical long-slit spectra and direct imaging (ground-based and with HST) of the pre-planetary nebula (pPN) M2-56 obtained at different epochs. The optical nebula is composed by shock-excited material distributed in two pairs of…

The author reports a result of an interferometric observation of the semiragular pulsating star with an unusual narrow molecular line profile, X Her, in the CO J=1-0 line with the Berkeley-Illinois-Maryland array. In the CO spectrum, a…

In this contribution we give a progress report on our systematic study of a large sample of post-AGB stars. The sample stars were selected on the basis of their infrared colours and the selection criteria were tuned to discover objects with…

The circumstellar environment of the AGB star L$_{\rm 2}$ Puppis was observed with ALMA in cycle 3, with a resolution of $15 \times 18 \rm\ mas$. The molecular emission shows a differentially rotating disk, inclined to a nearly edge-on…

It is now well established that FGK post-AGB stars that are surrounded by both hot and cold dust (as derived from the spectral energy distribution), are almost always part of a binary system with $100 < P_{orb} < 5000$~days. The properties…

We study the Galactic bulge planetary nebula M 2-29 (for which a 3-year eclipse event of the central star has been attributed to a dust disk) using HST imaging and VLT spectroscopy, both long-slit and integral field. The central cavity of M…

AGB stars, the precursors of Planetary Nebulae, exhibit high rates of mass loss and eject material in the form of a slow (10-20 km/s), dusty molecular wind. The general belief that the dust component of AGB circumstellar envelopes have…

Post-AGB stars are key objects for the study of the dramatic morphological changes of low- to intermediate-mass stars on their evolution from the Asymptotic Giant Branch (AGB) towards the Planetary Nebula stage. There is growing evidences…

Far-infrared Herschel PACS imaging and spectroscopic observations of the nebula around the luminous blue variable (LBV) star AG Car have been obtained along with optical imaging in the Halpha+[NII] filter. In the infrared light, the nebula…

We aim to constrain the structure of the circumstellar material around the post-AGB binary and RV Tauri pulsator AC Her. We want to constrain the spatial distribution of the amorphous as well as of the crystalline dust. We present very…

V921 Scorpii is a close binary system (separation 0.025") showing the B[e]-phenomenon. The system is surrounded by an enigmatic bipolar nebula, which might have been shaped by episodic mass-loss events, possibly triggered by dynamical…

We study the nature of Gomez's Hamburger (IRAS 18059-3211), a nebula that has been proposed to be a post-AGB object. Such a classification is not confirmed; instead, we argue that it will be a key object in the study of disks rotating…

Binary post-asymptotic giant branch (post-AGB) stars are thought to be the products of a strong but poorly-understood interaction during the AGB phase. The aim of this contribution is to update the orbital elements of a sample of galactic…