Related papers: Magnetic activity in close binary systems
Tidal forces in close binaries and multiple systems that contain magnetically active component are supposed to influence the operation of magnetic dynamo. Through synchronization the tidal effect of a close companion helps maintain fast…
Stellar activity is fundamental to stellar evolution and the formation and habitability of exoplanets. The interaction between convective motions and rotation in cool stars results in a dynamo process that drives magnetic surface activity.…
Thermal convection is commonly believed to be the energy source of stellar or planetary dynamo. In this short paper we provide another possibility, namely large-scale tidal flow. In close binary stars, say, solar-like stars with orbital…
In close binary stars, the tidal excitation of pulsations typically dissipates energy, causing the system to evolve towards a circular orbit with aligned and synchronized stellar spins. However, for stars with self-excited pulsations, we…
Tidal and tidal-resonant effects in coalescing compact binary systems are investigated by direct numerical integration of the equations of motion. For the stars polytropic models are used. The tidal effects are found to be dominated by the…
The architecture of many exoplanetary systems is different from the solar system, with exoplanets being in close orbits around their host stars and having orbital periods of only a few days. We can expect interactions between the star and…
The basic theory of dynamic tides in close binaries is reviewed. Particular attention is paid to resonances between dynamic tides and free oscillation modes and to the role of the apsidal-motion rate in probing the internal structure of…
We suggest a mechanism for enhancing magnetic activity in tidally interacting binaries. We suppose that the deviation of the primary star from spherical symmetry due to the tidal influence of the companion leads to stellar pulsation in its…
Surface reconstructions of active close binary stars based on photometric and spectroscopic observations reveal non-uniform starspot distributions, which indicate the existence of preferred spot longitudes (with respect to the companion…
We introduce a new model to explain the modulation of the orbital period observed in close stellar binary systems based on an angular momentum exchange between the spin of the active component and the orbital motion. This spin-orbit…
Using the LAMOST DR7 low-resolution spectra, we carried out a systematic study of stellar chromospheric activity in both single and binary stars. We constructed a binary sample and a single-star sample, mainly using the binary belt and the…
Tidal interaction between an exoplanet and its host star is a possible pathway to transfer angular momentum between the planetary orbit and the stellar spin. In cases where the planetary orbital period is shorter than the stellar rotation…
According to dynamo theory, stars with convective envelopes efficiently generate surface magnetic fields, which manifest as magnetic activity in the form of starspots, faculae, flares, when their rotation period is shorter than their…
We study how tides in a binary system induce some specific internal shear mixing, able to substantially modify the evolution of close binaries prior to mass transfer. We construct numerical models accounting for tidal interactions,…
We examine the dynamics of resonance locking in detached, tidally interacting binary systems. In a resonance lock, a given stellar or planetary mode is trapped in a highly resonant state for an extended period of time, during which the spin…
In this talk, we review some recent advances in the theory of dynamic tides in close binaries. We particularly focus on the effects of resonances of dynamic tides with free oscillation modes and on the role of dynamic tides in the…
To first approximation, a binary system conserves its angular momentum while it evolves to its state of minimum kinetic energy: circular orbit, all spins aligned, and components rotating in synchronism with the orbital motion. The pace at…
Stellar dynamos are driven by complex couplings between rotation and turbulent convection, which drive global-scale flows and build and rebuild stellar magnetic fields. When stars like our sun are young, they rotate much more rapidly than…
We study the excitation and damping of tides in close binary systems, accounting for the leading order nonlinear corrections to linear tidal theory. These nonlinear corrections include two distinct effects: three-mode nonlinear interactions…
The magnetic activity of solar-type stars generally increases with stellar rotation rate. The increase, however, saturates for fast rotation. The Babcock-Leighton mechanism of stellar dynamos saturates as well when the mean tilt-angle of…