Related papers: Internal magnetic fields, spin-orbit coupling, and…
A dynamics of the precession of coupled atomic moments in the tight-binding (TB) approximation is presented. By implementing an angular penalty functional in the energy that captures the magnetic effective fields self-consistently, the…
We present a general theory of multiorbital spin waves in magnetically ordered metallic systems. Motivated by the itinerant magnetism of iron-based superconductors, we compare the magnetic excitations for two different scenarios: when the…
This paper deals with the application of the creep tide theory (Ferraz-Mello, Cel. Mech. Dyn. Astron. vol. 116, 109, 2013) to the study of the rotation of stars hosting massive close-in planets. The stars have nearly the same tidal…
A rotating star's oblateness creates a deformation in the gravitational field outside the star, which is measured by the quadrupole-moment tensor. We consider the effect of the quadrupole moment on the orbital motion and rate of inspiral of…
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…
The presence of strong large-scale stable magnetic fields in a significant portion of early-type stars, white dwarfs, and neutron stars is well established. Despite this, the origins of these fields remain unresolved, with leading…
(abbreviated) We consider the problem of the tidal capture or circularisation from large eccentricity of a uniformly rotating object. We extend the self-adjoint formalism introduced in Papaloizou \& Ivanov 2005 (PI) to derive general…
Extrasolar circumbinary planets are so called because they orbit two stars instead of just one; to date, an increasing number of such planets have been discovered with a variety of techniques. If the orbital frequency of the hosting stellar…
Planets in close-in orbit interact with the magnetized wind of their hosting star. This magnetic interaction was proposed to be a source for enhanced emissions in the chromosphere of the star, and to participate in setting the migration…
The objective of this paper is to study the tidally locked 3:2 spin-orbit resonance of Mercury around the Sun. In order to achieve this goal, the effective potential energy that determines the spinning motion of an ellipsoidal planet around…
Planets have been observed in tight binary systems with separations less than 20 AU. A likely formation scenario for such systems involves a dynamical capture, after which high relative inclinations are likely and may lead to Kozai…
Spin-orbit misalignments have been detected in exoplanetary systems and binary star systems. Tidal interactions may have played an important role in the evolution of the spin-orbit angle. In this study, we investigate the tidal interactions…
In this paper we extend the previous work of Papaloizou \& Savonije on tidal interactions between a solar mass star and a closely orbiting giant planet which is such that the orbital and stellar spin angular momentum directions are…
In binary radio pulsar system J0737-3039, slow pulsar B shows orbital modulations of intensity, being especially bright at two short orbital phases. We propose that these modulations are due to distortion of pulsar B magnetosphere by pulsar…
Observational evidence of star-planet magnetic interactions (SPMI) in compact exo-systems have been looked for in the past decades. Indeed planets in close-in orbit can be magnetically connected to their host star, and channel Alfv\'en…
We report detailed X-ray observations of the unique binary system $\epsilon$ Lupi, the only known short-period binary consisting of two magnetic early-type stars. The components have comparably strong, but anti-aligned magnetic fields. The…
Evidence from the analysis of eclipsing binary systems revealed that late-type stars are larger and cooler than predicted by models, and that this is probably caused by stellar magnetic activity. In this work, we revisit this problem taking…
Some short-period, detached binary systems have recently been reported to experience very rapid orbital decay, much faster than is expected from the angular-momentum loss caused by gravitational radiation alone. As these systems contain…
The orbital decay of binary systems is a critical process for understanding the evolution of massive binary black holes (MBBHs) and binary star formation. Performing high-resolution three-dimensional magnetohydrodynamic (MHD) simulations,…
The class of Double Period Variables (DPVs) consists of close interacting binaries, with a characteristic long period that is an order of magnitude longer than the corresponding orbital period, many of them with a characteristic ratio of…