Related papers: Nonlinear Dynamics, Lorenz Model and Formation of …
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 investigate the impact of tidal interactions, before any mass transfer, on various properties of the stellar models. We study the conditions for obtaining homogeneous evolution triggered by tidal interactions, and for avoiding any Roche…
The non-stationary nonlinear models of magnetostatic waves propagation in layered ferromagnetic structures are developed. This models are based on use of the coupled nonlinear Schrodinger equations for amplitude of a bending around taking…
We illustrate how rotation of the central star can give rise to latitudinal variations in the wind properties from the star. Interaction of these winds with the surrounding medium can produce asymmetrical planetary nebulae.
Most stars with birth masses larger than that of our Sun belong to binary or higher order multiple systems. Similarly, most stars have stellar winds. Radiation pressure and multiplicity create outflows of material that remove mass from the…
We perform fully relativistic calculations of binary neutron stars in corotating, circular orbit. While Newtonian gravity allows for a strict equilibrium, a relativistic binary system emits gravitational radiation, causing the system to…
We discuss the formation and evolution of binaries which contain neutron stars or black holes. It is shown that in a stellar system which for $10^{10}$ yr had star formation rate similar to the current one in the Galactic disc, the rate of…
Binary galaxies are modeled as point-masses obeying the non-Newtonian MOND and Mannheim-Kazanas (MKG) theories of gravity. Random samples of such systems are generated by means of Monte Carlo simulations of binary orbits. Model pairs have…
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…
A number of efforts are underway to detect close binary stars in planetary nebulae. The primary goal of these studies is to determine the binary fraction of central stars. The next stage is a detailed analysis of the binaries to determine…
A 2D dynamic model is utilized to investigate star formation in rotating filamentary molecular clouds (FMCs) amidst magnetic fields. The study reveals that the emergence of field stars is possible under both weak and strong magnetic fields…
A survey of currently known planet-hosting stars indicates that approximately 25% of extrasolar planetary systems are within dual-star environments. Several of these systems contain stellar companions on moderately close orbits, implying…
Recent observations of young embedded clumpy clusters and statistical identifications of binary star clusters have provided new insights into the formation process and subsequent dynamical evolution of star clusters. The early dynamical…
Stellar models of massive single stars are still plagued by major uncertainties. Testing and calibrating against observations is essential for their reliability. For this purpose one preferably uses observed stars that have never…
I propose a scenario for the formation of double-ring systems, as observed in some planetary nebulae and in the outer rings of SN 1987A. In this scenario, two jets, one jet on each side of the equatorial plane, expand into a thin, dense…
The majority of stars in the Galactic field and halo are part of binary or multiple systems. A significant fraction of these systems have orbital separations in excess of thousands of astronomical units, and systems wider than a parsec have…
Overcontact binary stars are systems of two stars where the component stars are in contact with each other. This implies that they share a common envelope of gas. In this work we seek signatures of nonlinearity and chaos in these stars by…
In this review, we describe the physical processes driving the dynamical evolution of binary stars, namely the circularization of the orbit and the synchronization of their spin and orbital rotation. We also discuss the possible role of the…
Quasi-equilibrium sequences of binary neutron stars are constructed for a variety of equations of state in general relativity. Einstein's constraint equations in the Isenberg-Wilson-Mathews approximation are solved together with the…
Fragmentation and fission of giant molecular clouds occasionally results in a pair of gravitationally bound star clusters that orbit their mutual centre of mass for some time, under the influence of internal and external perturbations. We…