Related papers: DT Serpentis: neither a symbiotic star nor a plane…

The specific characteristic of the SED of serendipitously discovered post-AGB binaries, allowed us to launch a very extensive multi-wavelength study of evolved objects, selected on the basis of very specific selection criteria. Those…

The bright southern star L2 Pup is a particularly prominent asymptotic giant branch (AGB) star, as its distance of 64 pc makes it the nearest of its type. We report new adaptive optics observations of L2 Pup at visible wavelengths with the…

Context. We analyse the line and continuum spectra of the symbiotic system CH Cygni. Aims. To show that the colliding-wind model is valid to explain this symbiotic star at different phases. Methods. Peculiar observed features such as…

The beginning of photoionization marks the transition between the post-Asymptotic Giant Branch (post-AGB) and planetary nebula (PN) phases of stars with masses < 8 M_sun. This critical phase is difficult to observe, as it lasts only a few…

VLA surface brightness and spectral index maps of the evolving extended emission of the triple symbiotic star CH Cygni are presented. These are derived from observations at 4.8, 8.4 and 14GHz between 1985 and 1999. The maps are dominated by…

We report the detection, with ${\it Chandra}$ and XMM-${\it Newton}$, of faint, soft X-ray emission from four symbiotics stars that were not known to be X-ray sources. These four object show a $\beta$-type X-ray spectrum, i.e. their spectra…

We report on a near-infrared, long-baseline interferometric search for luminous companions to the star 51 Pegasi conducted with the Palomar Testbed Interferometer. Our data is completely consistent with a single-star hypothesis. We find no…

We present Hubble Space Telescope (HST) observations of the field of the Type IIb supernova (SN) 2011dh in M51 performed at ~1161 rest-frame days after explosion using the Wide Field Camera 3 and near-UV filters F225W and F336W. A star-like…

51 Pegasi harbors the first confirmed extrasolar planet orbiting a Sun-like star. Decades of continued radial velocity (RV) observations have since uncovered signatures of an additional distant companion in the system from a shallow radial…

Based on their stellar parameters and the presence of a mid-IR excess due to circumstellar dust, RV Tauri stars have been classified as post-AGB stars. Our recent studies, however, reveal diverse SEDs among RV Tauri stars, suggesting they…

We present and discuss initial selection criteria and first results in M33 from a systematic search for extragalactic symbiotic stars. We show that the presence of diffuse interstellar gas emission can significantly contaminate the spectra…

TESS observations of pulsating hot main sequence stars paint a very different picture from what is currently accepted. There are large numbers of delta Scuti (DSCT) stars hotter than the theoretical hot edge of the instability strip,…

Binary interactions dominate the evolution of massive stars, but their role is less clear for low- and intermediate-mass stars. The evolution of a spherical wind from an asymptotic giant branch (AGB) star into a nonspherical planetary…

About 3,500 planetary nebulae (PNe) are currently known in the Milky Way, which shows a great discrepancy with the expected number for these objects, regardless of the reference used, $33-59 \times 10^{3}$. The same holds for symbiotic…

We report on the results of the multiwavelength campaign carried out after the discovery of the INTEGRAL transient IGR J17329-2731. The optical data collected with the SOAR telescope allowed us to identify the donor star in this system as a…

In this paper, we study the general impact of stellar mass-ejection events in planetary orbits in post-common envelope binaries with circumbinary planets like those around NN Serpentis. We discuss a set of simple equations that determine…

Circumbinary disks are common around post-asymptotic giant branch (post-AGB) stars with a stellar companion on orbital time scales of a few 100 to few 1000 days. The presence of a disk is usually inferred from the system's spectral energy…

We present a new model atmosphere analysis of nine central stars of planetary nebulae. This study is based on a new generation of realistic stellar model atmospheres for hot stars; state-of-the-art, hydrodynamically consistent, spherically…

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…

We propose a new approach for studying the neutron star/supernova remnant associations, based on the idea that the supernova remnants (SNRs) can be products of an off-centered supernova (SN) explosion in a preexisting bubble created by the…