Related papers: Evidences on secular dynamical evolution of detach…
In this Paper we determine the non-dissipative tidal evolution of a close binary system with an arbitrary eccentricity in which the spin angular momenta of both components are misaligned with the orbital angular momentum. We focus on the…
In the absence of detectable pulsations in the eclipsing High Mass X-ray binary 4U 1700-37, the orbital period decay is necessarily determined from the eclipse timing measurements. We have used the earlier reported mid-eclipse time…
Six semi-detached Algol-type binaries lacking a period analysis were chosen to test for a presence of a third body. The O-C diagrams of these binaries were analyzed with the least-squares method by using all available times of minima. Also…
Assuming weakly guiding approximation, we examine orbital angular momentum (OAM) mode mixing on account of ellipticity in a fiber and derive a complete set of analytic expressions for spatial crosstalk, using scalar perturbation theory that…
It is generally thought that conservative mass transfer in Algol binaries causes their orbits to be wider, in which the less massive star overflows its Roche-lobe. The observed decrease in the orbital periods of some Algol binaries suggests…
We present a study of the evolutionary stage of the interacting binary and Double Periodic Variable AU Monocerotis. A multi-parametric Chi2 minimization is made between the observed parameters and those predicted by the grid of…
We postulate that most stars are born in aggregates of binary systems which are dynamically equivalent to the `dominant mode cluster'. The initial binary orbits are consitent with pre-main sequence data. Stellar masses are paired at random…
We have selected archival observational data for several O and B trapezia in the Milky Way. For each of the main components of the trapezia we obtained transverse velocities from the historical separation data. With this information, and…
We provide a generalized discussion of tidal evolution to arbitrary order in the expansion of the gravitational potential between two spherical bodies of any mass ratio. To accurately reproduce the tidal evolution of a system at separations…
Many binary stellar systems in which the primary star is beyond the asymptotic giant branch (AGB) evolutionary phase show significant orbital eccentricities whereas current binary interaction models predict their orbits to be circularised.…
The photometric and spectroscopic studies of six contact binaries were performed for the first time. The orbital periods of all the six targets are longer than 0.5d, and we discovered that their mass ratios are smaller than 0.15. So, they…
We report on nine wide common proper motion systems containing late-type M, L, or T companions. We confirm six previously reported companions, and identify three new systems. The ages of these systems are determined using diagnostics for…
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…
Complex period variations of five W UMa type binaries (AB And, OO Aql, DK Cyg, V566 Oph, U Peg) were investigated by analyzing their O--C diagrams, and several common features were found. Four of the five systems show secular period…
The hierarchical multiple system XY Leo, despite nearly 90 yr of observations, remains enigmatic. It offers a unique testbed for close binary evolution, involving processes such as mass transfer, angular momentum loss, and the von…
Liberal evolution of interacting binaries has been proposed previously by several authors in order to meet various observed binary characteristics better than conservative evolution does. Since Algols are eclipsing binaries the distribution…
The spin-down of a millisecond pulsar in a compact binary system leads to self-energy losses, that cause the binary's orbital period to increase (the effect being of first post-Newtonian (1PN) order). If the pulsar's period-derivative is…
Ultra-short orbital period contact binaries (Porb < 0.26 d) host some of the smallest and least massive stars. These systems are faint and rare, and it is believed that they have reached a contact configuration after several Gyrs of…
St 2-22 is a relatively poorly studied S-type symbiotic system that belongs to a small group of jet-producing systems as a result of disc accretion onto a white dwarf fed by its red giant companion. The goal of this paper is to analyse the…
Compact objects evolving in an astrophysical environment experience a gravitational drag force known as dynamical friction. We present a multipole-frequency decomposition to evaluate the orbit-averaged energy and angular momentum…