Related papers: Mergers via failed common envelope as a route towa…
Stars stripped of their envelope through interaction in a binary are generally not considered when accounting for ionizing radiation from stellar populations, despite the expectation that stripped stars emit hard ionizing radiation, form…
Post-main-sequence binary mergers are a common evolutionary pathway for massive stars, but the effects of merging on the long-term structure and evolution of the resulting star are a matter of active debate. Furthermore, the way in which…
Because the majority of massive stars are born as members of close binary systems, populations of massive main-sequence stars contain stellar mergers and products of binary mass transfer. We simulate populations of massive stars accounting…
A magnetic dynamo driven by differential rotation generated when stars merge can explain strong fields in certain classes of magnetic stars, including the high field magnetic white dwarfs (HFMWDs). In their case the site of the differential…
It is predicted that orbital decay by gravitational-wave radiation and tidal interaction will cause some close-binary stars to merge within a Hubble time. The merger of a helium-core white dwarf with a main-sequence star can produce a red…
Stars stripped of their hydrogen-rich envelopes through binary interaction are thought to be responsible for both hydrogen-poor supernovae and the hard ionizing radiation observed in low-$Z$ galaxies. A population of these stars was…
This chapter describes the current state of models of individual blue stragglers. Stellar collisions, binary mergers (or coalescence), and partial or ongoing mass transfer have all been studied in some detail. The products of stellar…
Stellar mergers and common-envelope evolution are fast (dynamical-timescale) interactions in binary stars that drastically alter their evolution. They are key to understanding a plethora of astrophysical phenomena. Stellar mergers are…
In the cores of young dense star clusters repeated stellar collisions involving the same object can occur, which has been suggested to lead to the formation of an intermediate-mass black hole. In order to verify this scenario we compute the…
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}$. However, only one candidate…
Stripped stars are hot, helium-rich stars formed when binary interactions remove a star's hydrogen envelope. While low-mass ($\lesssim 1 M_\odot$) and high-mass ($\gtrsim 8 M_\odot$) stripped stars are well studied as hot subdwarfs and…
Products of stellar mergers are predicted to be common in stellar populations and can potentially explain stars with peculiar properties. When the merger occurs after the initially more massive star has evolved into the Hertzsprung gap…
Most massive stars are born in binary or higher-order multiple systems and exchange mass with a companion during their lives. In particular, the progenitors of a large fraction of compact object mergers, and Galactic neutron stars (NSs) and…
We study the nucleosynthesis and the induced mixing during the merging of massive stars inside a common envelope. The systems of interest are close binaries, initially consisting of a massive red supergiant and a main-sequence companion of…
The majority of massive stars are formed in multiple systems and will interact with companions via mass transfer. This interaction typically leads to the primary shedding its envelope and the formation of a "stripped star". Classically,…
Binary interaction can cause stellar envelopes to be stripped, which significantly reduces the radius of the star. The orbit of a binary composed of a stripped star and a compact object can therefore be so tight that the gravitational…
More than half of all main-sequence (MS) stars have one or more companions, and many of those with initial masses <8 M$_\odot$ are born in hierarchical triples. These systems feature two stars in a close orbit (the inner binary) while a…
Standard binary evolutionary models predict a significant population of core helium-burning stars that lost their hydrogen-rich envelope after mass transfer via Roche-lobe overflow. However, there is a scarcity of observations of such…
A primary production mechanism for blue stragglers in globular clusters is thought to be collisionally-induced mergers, perhaps mediated by dynamical encounters involving binary stars. We model the formation and evolution of such blue…
Massive stars are often found in binary systems and it has been argued that binary products boost the ionizing radiation of stellar populations. Accurate predictions for binary products are needed to understand and quantify their…