Related papers: Dynamical Tide in Solar-Type Binaries
We calculate the tidal response of helium and carbon/oxygen (C/O) white dwarf (WD) binaries inspiraling due to gravitational wave emission. We show that resonance locks, previously considered in binaries with an early-type star, occur…
The diagram of indices of coronal and chromospheric activity allowed us to reveal stars where solar-type activity appears and regular cycles are forming. Using new consideration of a relation between coronal activity and the rotation rate,…
Main-sequence massive stars possess convective cores that likely harbor strong dynamo action. To assess the role of core convection in building magnetic fields within these stars, we employ the 3-D anelastic spherical harmonic (ASH) code to…
It is already known that about 10% of central stars of PNe are very short-period binaries (hours to days), which are detected through photometric variations. These must have been formed through common-envelope interactions in initially wide…
Repeatedly flaring X-ray binaries have recently been discovered in NGC 4697 by Sivakoff and collaborators. We show that these flares can be explained as the result of eccentric binaries in globular clusters which accrete more rapidly at…
About 50% of all known hot subdwarf B stars (sdBs) reside in close (short period) binaries, for which common envelope ejection is the most likely formation mechanism. However, Han et al. 2003 predict that the majority of sdBs should form…
In the present study we analyze the behavior of the rotational velocity, vsini, for a large sample of 134 spectroscopic binary systems with a giant star component of luminosity class III, along the spectral region from middle F to middle K.…
Asynchronous rotation in binary stars produces non-radial oscillations that are known to cause observable variability on orbital timescales. The horizontal perturbations of the surface velocity fields are referred to as "tidal flows". In…
During the final stages of a neutron-star binary coalescence, stellar quasi-normal modes can become resonantly excited by tidal fields. If the strain exerted by the excited modes exceeds the extent to which the crust can respond linearly,…
We re-analyze the pristine eclipsing binary data from the $\textit{Kepler}$ and TESS missions, focusing on eccentricity measurements at short orbital periods to emperically constrain tidal circularization. We find an average circularization…
A binary in which a slightly evolved star starts mass transfer to a neutron star can evolve towards ultra-short orbital periods under the influence of magnetic braking. This is called magnetic capture. We investigate in detail for which…
Early-type stars have convective cores due to a steep temperature gradient produced by the CNO cycle. These cores can host dynamos, and the generated magnetic fields can be relevant to explain the magnetism observed in Ap/Bp stars. Our main…
We present the results of the first theoretical non-radial non-adiabatic pulsational study of M dwarf stellar models with masses in the range 0.1 to 0.5M_solar. We find the fundamental radial mode to be unstable due to an \epsilon mechanism…
We consider the tidal excitation of modes in a binary system of arbitrary eccentricity. For a circular orbit, the modes generally undergo forced oscillation with a period equal to the orbital period ($T$). For an eccentric orbit, the…
We study the tidal evolution of a binary system consisting of a 1.4 Msun compact object in elliptic orbit about a 10 Msun uniformly rotating main sequence star for various values of the initial orbital parameters. We apply our previously…
We propose a star-quake model to understand X-ray flares of both long and short Gamma-ray bursts (GRBs) in a solid quark star regime. Two kinds of central engines for GRBs are available if pulsar-like stars are actually (solid) quark stars,…
Rotation contributes to internal mixing processes and observed variability in massive stars. A significant number of binary stars are not in strict synchronous rotation, including all eccentric systems. This leads to a tidally induced and…
The presence of r mode oscillations (global modes of Rossby waves coupled with buoyancy) in an eclipsing binary is recognized as frequency groups in a frequency-amplitude diagram obtained from a Fourier analysis of Kepler light curve data.…
Carbon-enhanced metal-poor stars, CH stars and barium stars, among other classes of chemically peculiar stars, are thought to be products of the interaction of low- and intermediate-mass binaries which occurred when the most evolved star…
We show that substantially enhanced mass loss at periastron passages, as is expected in the grazing envelope evolution (GEE), can compensate for the circularization effect of the tidal interaction in binary systems composed of an asymptotic…