Related papers: Kinematics of the chromospherically active binarie…
The evolution of contact binary star systems in mass asymmetry (transfer) coordinate is considered. The orbital period changes is explained by an evolution in mass asymmetry towards the symmetry (symmetrization of binary system). It is…
The massive (13,000-26,000 Msolar), young (15-30 Myr) Large Magellanic Cloud star cluster NGC 1818 reveals an unexpected increasing binary frequency with radius for F-type stars (1.3-2.2 Msolar). This is in contrast to many older star…
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 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…
Binary stars are common. While only those with small separations may exchange gas with one another, even the widest binaries interact with their gaseous surroundings. Drag forces and accretion rates dictate how these systems are transformed…
Our aim is to calculate the evolution of Algol binaries within the framework of the osculating orbital theory, which considers the perturbing forces acting on the orbit of each star arising from mass exchange via Roche lobe overflow (RLOF).…
We study the long-term orbital evolution of stars around a merging massive or supermassive black-hole (BH) binary, taking into account the general relativistic effect induced by the BH spin. When the BH spin is significant compared to and…
Binary stars are predicted to have an important role in the evolution of globular clusters, so we obtained binary fractions for 35 globular clusters that were imaged in the F606W and F814W with the ACS on the Hubble Space Telescope. When…
We report the results from our analysis of 8 years of the data for the gamma-ray binary LS I +61 303, obtained with the Large Area Telescope onboard the Fermi Gamma-Ray Space Telescope. We find a significant dip around the binary's…
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…
From recent large observing campaigns, one finds that nearly all non- or weakly magnetic cataclysmic variables in the orbital period range between 2.8 and 4 hours are of SW Sex type and as such experience very high mass transfer rates. The…
Context. Mass loss is an important property in evolution models of massive stars. As up to 90% of the massive stars have a visual or spectroscopic companion and many of them exhibit mass exchange, mass-loss rates can be acquired through the…
Gyrochronology enables the derivation of ages of late-type main sequence stars based on their rotation periods and a mass proxy, such as color. It has been explored in open clusters, but a connection to field stars has yet to be…
Recent observations of binary stars in the Galactic field show that the binary fraction and the mean orbital separation both decrease as a function of decreasing primary mass. We present $N$-body simulations of the effects of dynamical…
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…
We study the evolution of circumbinary disks under the gravitational influence of the binary using two-dimensional hydrodynamical simulations to investigate the impact of disk and binary parameters on the dynamical aspects of the disk. To…
We study the occurrence of spectroscopic binaries in young star-forming regions using the INfrared Spectroscopy of Young Nebulous Clusters(IN-SYNC) survey, carried out in SDSS-III with the APOGEE spectrograph. Multi-epoch observations of…
We reexamine evolutionary channels for the formation of binary millisecond pulsars in order to understand their observed orbital period distribution. The available paths provide a natural division into systems characterized by long orbital…
We have used precise radial velocity measurements for a large number of candidate low-mass stars and brown dwarfs, to show that the young Sigma Ori ``cluster'' consists of two spatially superimposed components which are kinematically…
Main aim of this paper is the first light curve and apsidal motion analysis of thirteen eccentric eclipsing binaries and to reveal their basic physical properties. All of the systems were studied by method of period analysis of times of…