Related papers: Binary Red Supergiants: A New Method for Detecting…
Most known white dwarfs in multiple systems with main sequence stars have been discovered with M-type companions, because the white dwarf causes detectable UV excess and bluer colors than expected from a single M star. Surveys have shown…
The binary status of gamma-Cas stars has been discussed while theoretically examining the origin of their peculiar X-ray emission. However, except in two cases, no systematic radial velocity monitoring of these stars had been undertaken yet…
A large number of high-dispersion spectra of classical Cepheids were obtained in the region of the CaII H+K spectral lines. The analysis of these spectra allowed us to detect the presence of a strong Balmer line, H$\epsilon$, for several…
The light curves and spectra of many Type I and Type II supernovae (SNe) are heavily influenced by the interaction of the SN ejecta with circumstellar material (CSM) surrounding the progenitor star. The observed diversity shows that many…
We used a set of archived HST/WFPC2 images to probe the stellar population in the core of the nearby Galactic Globular Cluster (GGC) 47 Tuc. From the ultraviolet (UV) Color Magnitude Diagrams (CMDs) obtained for ~4,000 stars detected within…
Context: We present a newly discovered class of low-luminosity, dusty, evolved objects in the Magellanic Clouds. These objects have dust excesses, stellar parameters, and spectral energy distributions similar to those of dusty…
Classical Cepheids, like binary stars, are laboratories for stellar evolution and Cepheids in binary systems are especially powerful ones. About one-third of Galactic Cepheids are known to have companions and Cepheids in eclipsing binary…
We describe a near-IR photometric search for cool red dwarf companions to hot EUV-detected white dwarfs (WDs). While some composite systems have been found optically among WDs detected in recent EUV All-Sky Surveys, we develop an IR…
Observations have definitively strengthened the long-standing assertion that binaries are crucial in massive star evolution. While the percentage of spectroscopic binary systems among main-sequence O stars is well-studied, other phases of…
It is currently admitted that an AGB star in a binary system is likely to pollute its companion with carbon- and s-process-rich matter. After the AGB star has faded into an unconspicuous white dwarf, the polluted companion enters the zoo of…
Detecting binary stars in photometric time series is traditionally done by measuring eclipses. This requires the orbital plane to be aligned with the observer. A new method without that requirement uses stellar oscillations to measure…
Constraints from surveys of post common envelope binaries (PCEBs) consisting of a white dwarf plus an M-dwarf companion have led to significant progress in our understanding of the formation of close white dwarf binary stars with low-mass…
Barium stars and technetium-poor, extrinsic S stars are binary systems with a white dwarf companion, and with orbital elements similar to those of symbiotic systems. One may thus wonder whether these various families of binary systems…
The center of the Galaxy harbors a supermassive black hole, Sgr\,A*, which is surrounded by a massive star cluster known as the S-cluster. The most extensively studied star in this cluster is the B-type main-sequence S2 star (also known as…
We report the discovery of two binary systems, each consisting of a slightly bloated G-type main-sequence star and an unseen companion, identified through photometric data from TESS and radial velocity variation from Gaia. High-resolution…
It is well established that magnetars are neutron stars with extreme magnetic fields and young ages, but the evolutionary pathways to their creation are still uncertain. Since most massive stars are in binaries, if magnetars are a frequent…
Yellow and red supergiants are evolved massive stars whose numbers and locations on the HR diagram can provide a stringent test for models of massive star evolution. Previous studies have found large discrepancies between the relative…
Stellar evolutionary models predict that most of the early type subdwarf stars in close binary systems have white dwarf companions. More massive companions, such as neutron stars or black holes, are also expected in some cases. The presence…
Self-lensing (SL) in binary systems has the potential to provide a unique observational window into the Galactic population of compact objects. Using the $\mathtt{startrack}$ and COSMIC population synthesis codes, we investigate how…
Binary companions to asymptotic giant branch (AGB) stars are an important aspect of their evolution. Few AGB companions have been detected, and in most cases it is difficult to distinguish between main-sequence and white dwarf companions.…