Related papers: An observational test of common-envelope evolution
We compare eighteen binary systems with precisely determined radii and masses from 23 to 1.1 M_sol, and stellar evolution models produced with our newly revised code TYCHO. ``Overshooting'' and rotational mixing were suppressed in order to…
We propose a common envelope evolution (CEE) scenario where a red giant branch (RGB) star engulfs a planet during its core helium flash to explain the puzzling system WD 1856+534 where a planet orbits a white dwarf (WD) of mass 0.52Mo with…
Establishing a large sample of post common envelope binaries (PCEBs) that consist of a white dwarf plus an intermediate mass companion star of spectral type AFGK, offers the potential to provide new constraints on theoretical models of…
We explore the initial conditions that lead to detached binary evolution of massive pre-MS binaries and ask how large a fraction of the observed binary systems may have been initially formed as low-mass protobinaries and later undergone a…
Standard stellar evolution theory poorly predicts the surface abundances of chemical species in low-mass, red giant branch (RGB) stars. Observations show an enhancement of p-p chain and CNO cycle products in red giant envelopes, which…
Studies of fundamental parameters of very low-mass objects are indispensable to provide tests of stellar evolution models that are used to derive theoretical masses of brown dwarfs and planets. However, only objects with dynamically…
In order to investigate the possible influence of rotation on the efficiency of the first dredge-up we determined atmospheric parameters, masses, and abundances of carbon, nitrogen, and oxygen in a sample of evolved intermediate mass stars.…
We present small-scale three-dimensional hydrodynamical simulations of the evolution of a 0.3Msun main sequence star which launches two perpendicular jets within the envelope of a 0.88Msun red giant. Based on previous large-scale…
Massive quiescent galaxies at high redshift are significantly more compact than their present-day counterparts. We investigate the roles, in determining this evolution, of major and minor mergers, and of the accretion of diffuse envelopes…
Modern tools for modeling stellar evolution, such as MESA (Modules for Experiments in Stellar Astrophysics), offer state-of-the-art implementations of stellar theories. However, this parametric approach introduces many free parameters that…
We aim to study the progenitor properties and expected rates of the two lowest-mass binary black hole (BH) mergers, GW 151226 and GW 170608, detected within the first two Advanced LIGO-Virgo runs, in the context of the isolated…
Binary population synthesis (BPS) study provides a comprehensive way to understand evolutions of binaries and their end products. Close white dwarf (WD) binaries have crucial characteristics in examining in uence of yetunresolved physical…
We present the results of spectroscopic observations of two eclipsing WR+OB-type systems - CQ Cep and CX Cep, performed in 2020-2023 with a low-resolution slit spectrograph TDS ($\lambda\lambda= 3660-7410$\AA, $R = 1300-2500$) on 2.5-m…
We review three main results of our recent study: * We show that a proper treatment of the tidal interaction prior to the onset of the common envelope (CE) leads to an enhance mass loss. This might increase the survivability of planets and…
A grid of evolutionary sequences of stars in the mass range $1.2$-$7$ M$_{\odot}$, with solar-like initial composition is presented. We focus on this mass range in order to estimate the masses and calculate the CNO surface abundances of a…
The chemical enrichments detected in CEMP-$s$ stars are believed to be the consequence of a mass-transfer episode from a now extinct AGB primary star. This hypothesis is borne out by the fact that most CEMP-$s$ stars exhibit RV variations…
We performed numerical simulations of the common envelope (CE) interaction between two intermediate-mass asymptotic giant branch (AGB) stars and their low-mass companions. For the first time, formation and growth of dust in the envelope is…
At least one in five of all planetary nebulae are the product of a common envelope (CE) interaction, where the companion in-spirals into the envelope of an asymptotic giant branch (AGB) star ejecting the nebula and leaving behind a compact…
We perform 3D hydrodynamical simulations to study recombination and ionization during the common envelope (CE) phase of binary evolution, and develop techniques to track the ionic transitions in time and space. We simulate the interaction…
Binary stellar evolution has been studied as important pathway to initiate various transient events like supernovae (SNe). Although the common envelope (CE) in a binary, outcomes of the CE and conditions for the SN explosion during the CE…