Related papers: A PIONIER View on Mass-Transferring Red Giants

Symbiotic stars are long-period interacting binaries where the compact objects, most commonly a white dwarf, is embedded in the dense stellar wind of an evolved companion star. UV and soft X-ray emission of the accretion disk and nuclear…

The stability criteria of rapid mass transfer and common-envelope evolution are fundamental in binary star evolution. They determine the mass, mass ratio, and orbital distribution of many important systems, such as X-ray binaries, type Ia…

We analyze two binary systems containing giant stars, V723 Mon ("the Unicorn") and 2M04123153+6738486 ("the Giraffe"). Both giants orbit more massive but less luminous companions, previously proposed to be mass-gap black holes. Spectral…

We investigate the evolution of interacting binaries where the donor star is a low-mass giant more massive than its companion. It is usual to assume that such systems undergo common-envelope (CE) evolution, where the orbital energy is used…

Over the last decade, evidence has accumulated that massive stars do not typically evolve in isolation but instead follow a tumultuous journey with a companion star on their way to core collapse. While Roche-lobe overflow appears…

Understanding the evolution of massive binary stars requires accurate estimates of their masses. This understanding is critically important because massive star evolution can potentially lead to gravitational wave sources such as binary…

Surface lithium is depleted when a star goes through the first dredge-up phase, yet $1\%$ of red giants are found to be Li-rich. The formation mechanism for these remains uncertain. We combine observational constraints from GALAH Li-rich…

We discuss some aspects of stellar evolution in binary systems. While single stars can swell following the chemical evolution of their interior, stars belonging to binary systems cannot overflow the size of the Roche lobe and hydrostatic…

We have measured the rotational velocities (v.sini) of the mass donors in a number of D'--type symbiotic stars, using the cross-correlation function method. Four from five D' symbiotic stars with known v.sini, appeared to be very fast…

Close-in planets are in jeopardy as their host stars evolve off the main sequence to the subgiant and red giant phases. In this paper, we explore the influences of the stellar mass (in the range 1.5--2\Mso ), mass-loss prescription, planet…

Binary systems of a hot subdwarf B (sdB) star + a white dwarf (WD) with orbital periods less than 2-3 hours can come into contact due to gravitational waves and transfer mass from the sdB star to the WD before the sdB star ceases nuclear…

Symbiotic stars are thought to show distinct X-ray emission from the accreting object and from the colliding winds of the two stars. I show that the colliding wind component is unnecessary. Instead, the spectra can be interpreted as…

LIN 358 and SMC N73 are two symbiotic binaries in the halo of the Small Magellanic Cloud, each composed of a hot white dwarf accreting from a cool giant companion. In this work, we characterize these systems using a combination of…

Turbulent motions in the convective envelope of red giants excite a rich spectrum of solar-like oscillation modes. Observations by CoRoT and Kepler have shown that the mode amplitudes increase dramatically as the stars ascend the red giant…

Symbiotic stars, binary pairs with a cool giant fueling accretion onto a hot compact companion, offer unique insights to our understanding of stellar evolution. Yet, only a few hundred symbiotic stars are confirmed. Here, we report on a new…

The elemental abundances of symbiotic giants are essential to address the role of chemical composition in the evolution of symbiotic binaries, to map their parent population, and to trace their mass transfer history. However, the number of…

Unstable mass transfer in binary systems can lead to transients such as luminous red novae (LRNe). Observations of such transients are valuable for understanding and testing models of mass transfer. For donor stars in the Hertzsprung gap,…

We study the nucleosynthesis and the induced mixing during the merging of massive stars inside a common envelope. The systems of interest are close binaries, initially consisting of a massive red supergiant and a main-sequence companion of…

Context. The mass-loss mechanism of cool massive evolved stars is poorly understood. The proximity of Betelgeuse makes it an appealing target to study its atmosphere, map the shape of its envelope, and follow the structure of its wind from…

Symbiotic stars are the long period, binary systems of strongly interacting stars at the final stages of evolution which can be useful tool to understand the chemical evolution of the Galaxy and the formation of stellar populations.…