Related papers: Chemically homogeneous evolution in massive binari…
Massive star evolutionary models generally predict the correct ratio of WC-type and WN-type Wolf-Rayet stars at low metallicities, but underestimate the ratio at higher (solar and above) metallicities. One possible explanation for this…
We consider essential mechanisms for orbit-shrinkage or "hardening" of compact binaries in globular clusters to the point of Roche-lobe contact and X-ray emission phase, focussing on the process of collisional hardening due to encounters…
A large fraction of stars are in binary systems, yet the evolution of proto-planetary discs in binaries has been little explored from the theoretical side. In this paper we investigate the evolution of the discs surrounding the primary and…
This paper reviews our knowledge on binary central stars of planetary nebulae and presents some personal opinions regarding their evolution. Three types of interactions are distinguished: type I, where the binary companion induces the mass…
The nucleosynthesis of heavy elements in the scenario for the evolution of a close binary of neutron stars differing greatly in mass is considered. In contrast to the scenario for the merger of two neutron stars of comparable masses…
Most globular clusters (GCs) show evidence for multiple stellar populations, suggesting the occurrence of several distinct star-formation episodes. The large fraction of second population (2P) stars observed requires a very large 2P gaseous…
Binaries that merge within the local Universe originate from progenitor systems that formed at different times and in various environments. The efficiency of formation of double compact objects is highly sensitive to metallicity of the star…
The early-R stars are carbon-rich K-type giants. They are enhanced in C12, C13 and N14, have approximately solar oxygen, magnesium isotopes, s-process and iron abundances, have the luminosity of core-helium burning stars, are not rapid…
The past decade has seen a revolution in our understanding of protoplanetary disk evolution and planet formation in single star systems. However, the majority of solar-type stars form in binary systems, so the impact of binary companions on…
Most massive stars experience binary interactions in their lifetimes that can alter both the surface and core structure of the stripped star with significant effects on their ultimate fate as core-collapse supernovae. However, core-collapse…
Wide gravitationally bound pairs of stars can be formed from adjacent prestellar cores that happen to move slowly enough relative to each other. These binaries are remnants of the primordial clustering. It is shown that the expected…
The environment near super massive black holes (SMBHs) in galactic nuclei contain a large number of stars and compact objects. A fraction of these are likely to be members of binaries. Here we discuss the binary population of stellar black…
The majority of all stars are members of a binary system. The evolution of such binary stars and their subsequent production of pairs of compact objects in tight orbits, such as double neutron stars and double black holes, play a central…
The surroundings of massive protostars constitute an accretion disc which has numerically been shown to be subject to fragmentation and responsible for luminous accretion-driven outbursts. Moreover, it is suspected to produce close binary…
The majority of close massive binary stars with initial periods of a few days experience a contact phase, in which both stars overflow their Roche lobes simultaneously. We perform the first dedicated study of the evolution of massive…
The question whether the interaction of a circumbinary disc with the central binary system leads to shrinking or expansion of the binary orbit has attracted considerable interest as it impacts the evolution of binary black holes and stellar…
At metallicities lower than that of the Small Magellanic Cloud, it remains essentially unexplored how fossil magnetic fields, forming large-scale magnetospheres, could affect the evolution of massive stars, thereby impacting the fundamental…
Rotation and mass loss are crucially interlinked properties of massive stars, strongly affecting their evolution and ultimate fate. Massive stars rotating near their breakup limit shed mass centrifugally, creating Be stars with…
Close-orbit binaries consisting of two compact objects are a center of attention because of the detection of gravitational-radiation-induced mergers. The creation of close, compact-object binaries involves physical processes that are not…
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…