Related papers: Core-envelope decoupling drives radial shear dynam…
The dynamical shear instability is an important mixing process in the advanced stages of the evolution of massive stars. We calculated different models of 15 Mo with an initial rotational velocity, v(rot,ini)= 300 km/s to investigate its…
We evolve stellar models to study the rotational profiles of the pre-explosion cores of single massive stars that are progenitors of core collapse supernovae (CCSNe), and find large rotational shear above the iron core that might play an…
Recent asteroseismic analyses have revealed the presence of strong (B $\gtrsim 10^5$ G) magnetic fields in the cores of many red giant stars. Here, we examine the implications of these results for the evolution of stellar magnetic fields,…
Using the formalism of general relativity for axially symmetric gravitational fields and their sources - rotating compact stars - a perturbation theory with respect to angular velocity is developed and physical quantities such as mass,…
Rotation is expected to have an important influence on the structure and the evolution of stars. However, the mechanisms of angular momentum transport in stars remain theoretically uncertain and very complex to take into account in stellar…
The magnetic field associated with neutron stars is generally believed to be threaded inside the star. In the presence of a magnetic field, the plasma present in the interior of the star goes through several processes that lead to magnetic…
The rotation rates in the deep interior and at the surface of 22 main-sequence stars with masses between $1.0$ and $1.6\,{\rm M}_{\odot}$ are constrained by combining asteroseismological analysis with spectroscopic measurements. The…
Star-planet tidal interactions play a significant role in the dynamical evolution of close-in planetary systems. We investigate the propagation and dissipation of tidal inertial waves in a stellar/planetary convective region. We take into…
Wide-field high precision photometric surveys such as Kepler have produced reams of data suitable for investigating stellar magnetic activity of cooler stars. Starspot activity produces quasi-sinusoidal light curves whose phase and…
The high quiescent X-ray luminosity observed in some magnetars is widely attributed to the decay and evolution of their ultra-strong magnetic fields. Several dissipation mechanisms have been proposed, each operating with different…
Observations of late-type main-sequence stars have revealed empirical scalings of coronal activity versus rotation period or Rossby number $Ro$ (a ratio of rotation period to convective turnover time) which has hitherto lacked explanation.…
Differential rotation in stars generates toroidal magnetic fields whenever an initial seed poloidal field is present. The resulting magnetic stresses, along with viscosity, drive the star toward uniform rotation. This magnetic braking has…
Magnetic fields can be created in stably stratified (non-convective) layers in a differentially rotating star. A magnetic instability in the toroidal field (wound up by differential rotation) replaces the role of convection in closing the…
Dense star clusters expand until their sizes are limited by the tidal field of their host galaxy. During this expansion phase the member stars evolve and lose mass. We show that for clusters with short initial relaxation time scales (<~100…
We perform a numerical parameter study to determine what effect varying differential rotation and flux emergence has on a star's non-potential coronal magnetic field. In particular we consider the effects on the star's surface magnetic…
The presence of giant gaseous planets that reside in close proximity to their host stars may be a consequence of large-scale radial migration through the proto-planetary nebulae. Within the context of this picture, significant orbital…
The differential rotation of anti-solar type detected by observations for several stars may result from a fast meridional flow. The sufficiently intensive meridional circulation may be caused by large-scale thermal inhomogeneities or,…
It is well known that neutron stars spin down due to magnetic dipole radiation. The deconfinement phase transition of hadron matter to quark matter is expected to occur in the dense cores of the stars during spin-down. The phase transition…
Using observations from the SOHO, STEREO and Hinode, we investigate magnetic field evolution in an equatorial coronal hole region. Two dipoles emerge one by one. The negative element of the first dipole disappears due to the interaction…
While the mission's primary goal was focused on exoplanet detection and characterization, Kepler made and continues to make extraordinary advances in stellar physics. Stellar rotation and magnetic activity are no exceptions. Kepler allowed…