Related papers: A PIONIER View on Mass-Transferring Red Giants
In a high-mass X-ray binary (HMXB) a massive star interacts with a neutron-star or black-hole companion in various ways. The gravitational interaction enables the measurement of fundamental parameters such as the mass of both binary…
The concept of central super-massive stars (${\cal M} \ge 5 \times 10^4 M_{\odot}$, where ${\cal M}$ is the mass of the super-massive star) embedded in dense stellar systems was suggested as a possible explanation for high- energy emissions…
In some semi-detached binary systems, the donor star may transfer mass to the companion at a very high rate. We propose that, at sufficiently high mass-transfer rates such that the accretion disk around the companion becomes geometrically…
The theory of binary evolution predicts that many massive stars should lose their hydrogen-rich envelopes via interaction with a companion -- revealing hot helium stars with masses of $\sim$2--8M$_{\odot}$. However, only one candidate…
Symbiotic stars are among the most crucial binary systems for studying binary star interactions and Type Ia supernova progenitors. Based on the unique observational characteristics of symbiotic stars, strong H I, He I emission lines, giant…
The internal properties of stars in the red-giant phase undergo significant changes on relatively short timescales. Long near-uninterrupted high-precision photometric timeseries observations from dedicated space missions such as CoRoT and…
A major outstanding problem in stellar astrophysics lies in understanding the wind generation mechanism by which evolved giants lose mass. Phase-resolved observations of eclipsing symbiotic binary systems, containing a mass-losing giant and…
Hot subdwarf (SD) stars are the stripped cores of red giant stars in transition to the white dwarf sequence. The B-type subdwarfs (sdB) are powered by helium fusion in the core, more evolved ones (sdO) by shell burning. Low mass SDs may…
Most current models of low mass red giant stars do not reproduce the observed position of the red giant branch luminosity bump, a diagnostic of the maximum extent of the convective envelope during the first dredge up. Global asteroseismic…
In symbiotic binaries, jets and disk winds may be integral to the physics of accretion onto white dwarfs from cool giants. The persistent outflow from symbiotic star MWC 560 (=V694 Mon) is known to manifest as broad absorption lines (BALs),…
In this article we study the nature of the recently identified populations of hot companions to red supergiant stars (RSGs). To this end, we compile the literature on the most well characterised systems with the aim of better understanding…
We evaluate the prompt observational signatures of the merger between a massive close-in planet (a `hot Jupiter') and its host star, events with an estimated Galactic rate of ~0.1-1/yr. Depending on the ratio of the mean density of the…
(Invited Review) According to modern definition, a symbiotic nova is an otherwise normal nova (i.e. powered by explosive thermonuclear burning) that erupts within a symbiotic star, which is a binary where a WD accretes from a cool giant…
We have simulated a common envelope interaction of a 0.88-M$_{\odot}$, 90-R$_{\odot}$, red giant branch star and a 0.6-M$_{\odot}$, compact companion with the smoothed particle hydrodynamics code, Phantom, from the beginning of the Roche…
Asteroseismic studies of red giants generally assume that the oscillation modes can be treated as linear perturbations to the background star. However, observations by the Kepler mission show that the oscillation amplitudes increase…
Before binary components interact, they evolve as single stars do. We therefore first critically discuss massive single star processes which affect their evolution, stellar wind mass loss and rotation in particular. Next we consider binary…
We present optical follow-up of IGR J16194-2810, a hard X-ray source discovered by the INTEGRAL mission. The optical counterpart is a $\sim500\,L_\odot$ red giant at a distance of $2.1$ kpc. We measured 17 radial velocities (RVs) of the…
The mass-transfer scenario links chemical peculiarities with stellar duplicity for an increasing number of stellar classes (classical and dwarf barium stars, subgiant and giant CH stars, S stars without technetium, yellow symbiotic stars,…
Close binary systems of compact stars, due to the emission of gravitational radiation, may evolve into a phase in which the less massive star transfers mass to its companion. We describe mass transfer by using the model of Roche lobe…
A common-envelope (CE) phase occurs when a star engulfs its companion and is widely considered the primary channel for producing Luminous Red Novae (LRNe). In this study, we combine binary-population synthesis with stellar-evolution…