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Related papers: Tidal dynamo in solar-like close binary stars

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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…

Solar and Stellar Astrophysics · Physics 2019-11-27 A. F. Lanza

We calculate the tidal torque on a uniformly rotating 1 Msun star at various stages of core hydrogen burning by an orbiting companion. We apply the `traditional approximation' and solve the radial part of the tidal perturbations by matrix…

Astrophysics · Physics 2009-11-07 G. J. Savonije , M. G. Witte

Surface magnetic fields have been detected in 5 to 10% of isolated massive stars, hosting outer radiative envelopes. They are often thought to have a fossil origin, resulting from the stellar formation phase. Yet, magnetic massive stars are…

Solar and Stellar Astrophysics · Physics 2019-09-25 Jérémie Vidal , David Cébron , Asif Ud-Doula , Evelyne Alecian

Circularization of late-type main-sequence binaries is usually attributed to turbulent convection, while that of early-type binaries is explained by resonant excitation of g modes. We show that the latter mechanism operates in solar-type…

Astrophysics · Physics 2009-10-30 Jeremy Goodman , Eric S. Dickson

Stellar oscillations are excited in non-synchronously rotating stars in binary systems due to the tidal forces. Tangential components of the tides can drive a shear flow which behaves as a differentially forced rotating structure in a…

The solar activity cycle is a manifestation of the hydromagnetic dynamo working inside our star. The detection of activity cycles in solar-like stars and the study of their properties allow us to put the solar dynamo in perspective,…

Solar and Stellar Astrophysics · Physics 2015-05-14 A. F. Lanza

The periods of magnetic activity cycles in the Sun and solar-type stars do not exhibit a simple or even single trend with respect to rotation rate or luminosity. Dynamo models can be used to interpret this diversity, and can ultimately help…

Solar and Stellar Astrophysics · Physics 2018-08-15 A. Strugarek , P. Beaudoin , P. Charbonneau , A. S. Brun

The magnetic fields of solar-type stars are observed to cycle over decadal periods -11 years in the case of the Sun. The fields originate in the turbulent convective layers of stars and have a complex dependency upon stellar rotation rate.…

Solar and Stellar Astrophysics · Physics 2017-08-02 A. Strugarek , P. Beaudoin , P. Charbonneau , A. S. Brun , J. -D. do Nascimento

Magnetohydrodynamic star-in-a-box simulations of convection and dynamos in a solar-like star with different rotation rates are presented. These simulations produce solar-like differential rotation with a fast equator and slow poles, and…

Solar and Stellar Astrophysics · Physics 2022-06-08 Petri J. Käpylä

Stellar systems consisting of multiple stars tend to undergo tidal interactions when the separations between the stars are short. While tidal phenomena have been extensively studied, a certain tidal effect exclusive to hierarchical triples…

Solar and Stellar Astrophysics · Physics 2018-06-27 Yan Gao , Alexandre C. M. Correia , Peter P. Eggleton , Zhanwen Han

The paper is devoted to the analysis of the systematic deviations between the classical formula for the rate of secular apsidal motion in close binaries and the formula established within the framework of the theory of dynamic tides. The…

Astrophysics · Physics 2009-11-07 B. Willems , A. Claret

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…

Solar and Stellar Astrophysics · Physics 2022-12-14 Charlotte Gehan , Patrick Gaulme , Jie Yu

The dissipation of the kinetic energy of wave-like tidal flows within the convective envelope of low-mass stars is one of the key physical mechanisms that shapes the orbital and rotational dynamics of short-period exoplanetary systems.…

Solar and Stellar Astrophysics · Physics 2019-11-06 A. Astoul , S. Mathis , C. Baruteau , F. Gallet , A. Strugarek , K. C. Augustson , A. S. Brun , E. Bolmont

Stars and planets in close systems are magnetised but the influence of magnetic fields on their tidal responses (and vice versa) and dissipation rates has not been well explored. We present exploratory nonlinear magnetohydrodynamical (MHD)…

Solar and Stellar Astrophysics · Physics 2025-07-18 Aurélie Astoul , Adrian J. Barker

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…

Astrophysics · Physics 2009-11-07 V. Holzwarth , M. Schuessler

Many stars exhibit strong magnetic fields, some of which are thought to be of primordial origin and others a sign of magnetic dynamo processes. We briefly review the results of observational studies of solar-type stars seeking to evaluate…

Astrophysics · Physics 2007-05-23 Allan Sacha Brun

Time-dependent insolation in a planetary atmosphere induces a mass quadrupole upon which the stellar tidal acceleration can exert a force. This "thermal tide" force can give rise to secular torques on the planet and orbit as well as radial…

Earth and Planetary Astrophysics · Physics 2009-01-21 Phil Arras , Aristotle Socrates

The direct measurements of the meridional flow velocities on stars are impossible today. To evaluate the meridional flow velocities on solar-like stars with stable activity periods, we supposed that during the stellar Hale cycle the matter…

Solar and Stellar Astrophysics · Physics 2014-06-10 Dilyara Baklanova , Sergei Plachinda

The turbulent viscosity of convection is believed to circularize the orbits of close binary stars. When the tidal period is shorter than the turnover time of the largest eddies, turbulent viscosity is believed to be suppressed. The degree…

Astrophysics · Physics 2009-10-30 Jeremy Goodman , Siang Peng Oh

We calculate the dynamical tides raised on a non-rotating solar-type star by a close stellar or planetary companion. Dissipation arising from a turbulent viscosity operating in the convection zone and radiative damping in the radiative core…

Astrophysics · Physics 2008-11-26 C. Terquem , J. C. B. Papaloizou , R. P. Nelson , D. N. C. Lin