Related papers: The Critical Mass Ratio for W UMa-type Contact Bin…

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…

Black hole - neutron star $(BH/NS)$ binaries are of interest in many ways: they are intrinsically multi-messenger systems, highly transient, radiate gravitational waves detectable by LIGO, and may produce $\gamma$-ray bursts. Although it…

The first binary neutron-star merger event, GW170817, and its bright electromagnetic counterpart have provided a remarkable amount of information. By contrast, the second event, GW190425, with $M_{\rm tot}=3.4^{+0.3}_{-0.1}\,M_{\odot}$ and…

Orbital angular momentum (Jo), systemic mass (M) and orbital period (P) distributions of chromospherically active binaries (CAB) and W Ursae Majoris (W UMa) systems were investigated. The diagrams of log Jo - log P, log M - log P and log…

We study a complete, colour-selected sample of double-degenerate binary systems containing extremely low mass (ELM) <0.25 Msol white dwarfs (WDs). We show, for the first time, that Milky Way disk ELM WDs have a merger rate of approximately…

In close binaries mass and angular momentum can be transferred from one star to the other during Roche-lobe overflow. The efficiency of this process is not well understood and constitutes one of the largest uncertainties in binary…

A large fraction of X-ray sources in our Galaxy are low-mass X-ray binaries, containing a black hole or a neutron star accreting from a gravitationally bound low-mass ($\leq$1 M$_\odot$) companion star. These systems are among the older…

We carry out a re-analysis of the photometric data in Cousin RI bands which was taken under the Nainital Microlensing Survey during 1998 to 2002 with the aim to detect gravitational microlensing events in the direction of M31. Here, we do…

The stability criteria of rapid mass transfer and common-envelope evolution are fundamental in binary star evolution. They determine the mass, mass ratio, and orbital distribution of many important systems, such as X-ray binaries, type Ia…

Using a population synthesis approach, we compute the total merger rate in the local Universe for double neutron stars, double black holes, and black hole -- neutron star binaries. These compact binaries are the prime source candidates for…

Stars are mostly found in binary and multiple systems, as at least 50% of all solar-like stars have companions - a fraction that goes up to 100% for the most massive stars. Moreover, a large fraction of them will interact in some way or…

Using near-infrared speckle interferometry we have obtained resolved JHK-photometry for the components of 58 young binary systems. From these measurements, combined with other data taken from literature, we derive masses and particularly…

Using state-of-the-art dynamical simulations of globular clusters, including radiation reaction during black hole encounters and a cosmological model of star cluster formation, we create a realistic population of dynamically-formed binary…

The dynamical formation of stellar-mass black hole-black hole binaries has long been a promising source of gravitational waves for the Laser Interferometer Gravitational-Wave Observatory (LIGO). Mass segregation, gravitational focusing, and…

Anticipating the kinematic constraints from the Gaia mission, we perform an extensive numerical study of the evolution of massive binary systems to predict the peculiar velocities that stars obtain when their companion collapses and…

We use the Galaxy And Mass Assembly (GAMA) survey to measure the local Universe mass dependent merger fraction and merger rate using galaxy pairs and the CAS structural method, which identifies highly asymmetric merger candidate galaxies.…

Mergers of black-hole binaries are expected to release large amounts of energy in the form of gravitational radiation. However, binary evolution models predict merger rates too low to be of observational interest. In this paper we explore…

Neutron stars and stellar-mass black holes are the remnants of massive stars, which ended their lives in supernova explosions. These exotic objects can only be studied in relatively rare cases. If they are interacting with close companions…

One of the most mysterious astrophysical states is the common envelope (CE) phase of binary evolution, in which two stars are enshrouded by the envelope shed by one of them. Interactions between the stars and the envelope shrinks the orbit.…

In numerical simulations of black hole binaries, Pretorius and Khurana [Class. Quant. Grav. {\bf 24}, S83 (2007)] have observed critical behaviour at the threshold between scattering and immediate merger. The number of orbits scales as…