Related papers: Internal magnetic fields, spin-orbit coupling, and…
We introduce a model for the orbital period modulation in systems with close-by giant planets based on a spin-orbit coupling that transfers angular momentum from the orbit to the rotation of the planet and viceversa. The coupling is…
The rotation period of some planet-hosting stars appears to be in close commensurability with the orbital period of their close-by planets. A model is proposed to interpret such a phenomenon based on the excitation of resonant oscillations…
A new mechanism for the internal heating of ultra-short-period planets is proposed based on the gravitational perturbation by a non-axisymmetric quadrupole moment of their host stars. Such a quadrupole is due to the magnetic flux tubes in…
The spin-induced quadrupole moment of a rapidly rotating star changes the orbital dynamics in a binary system, giving rise to advance (or regression) of periastron and precession of the orbital plane. We show that these effects are…
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…
We consider the evolution of a binary system interacting due to tidal effects without restriction on the orientation of the orbital, and where significant, spin angular momenta, and orbital eccentricity. We work in the low tidal forcing…
Short-period binary star systems dissipate orbital energy through tidal interactions that lead to tighter, more circular orbits. When at least one star in a binary has evolved off of the main sequence, orbital circularization occurs for…
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…
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…
Tidal forces in close binary systems have diverse impacts on magnetic activity. The synchronicity characteristic of close systems counteracts magnetic braking, thereby sustaining rapid rotation-a key factor in increased levels of magnetic…
Evidence of magnetic interaction between late-type stars and close-in giant planets is provided by the observations of stellar hot spots rotating synchronously with the planets and showing an enhancement of chromospheric and X-ray fluxes.…
Orbit spin coupling is proposed as an alternative to planetary tidal models for the excitation of solar variability as a function of time. Momentum sourced from the orbital angular momenta of solar system bodies is deposited within the…
Late-type stars interact with their close-in planets through their coronal magnetic fields. We introduce a theory for the interaction between the stellar and planetary fields focussing on the processes that release magnetic energy in the…
We outline a mechanism that explains the observed lack of circumbinary planets (CBPs) via coupled stellar-tidal evolution of isolated binary stars. Tidal forces between low-mass, short-period binary stars on the pre-main sequence slow the…
The magnetic activity of planet-hosting stars is an important factor to estimate the atmospheric stability of close-in exoplanets and the age of their host stars. It has long been speculated that close-in exoplanets can influence the…
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…
We present a new empirical calibration of equilibrium tidal theory for extrasolar planet systems, extending a prior study by incorporating detailed physical models for the internal structure of planets and host stars. The resulting strength…
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…
Years to decade-long cyclic period changes have been observed in many classes of close binaries. A common explanation invoked for these cyclic period changes is the gravitational influence of an unseen third body upon the close binary pair.…
Close-by planets may excite various kinds of oscillations in their host stars through their time-varying tidal potential. Magnetostrophic oscillations with a frequency much smaller than the stellar rotation frequency have recently been…