Related papers: Angular-momentum coupling through the tachocline
The simplest interior magnetic field B_i that can explain the observed uniform rotation of the Sun's radiative envelope is an axial dipole stabilized by a deep toroidal field. It can explain the uniform rotation only if confined in the…
We compare the current effects of rotation in stellar evolution to those of the magnetic field created by the Tayler instability. In stellar regions, where magnetic field can be generated by the dynamo due to differential rotation (Spruit…
The presence of turbulent phenomena in the outer solar atmosphere is a given. However, because we are reduced to remotely sensing the atmosphere of a star with instruments of limited spatial and/or spectral resolution, we can only infer the…
A new set of accurately measured frequencies of solar oscillations are used to infer the rotation rate inside the Sun, as a function of radial distance as well as latitude. We have adopted a regularized least squares technique with…
We examine the effects of the magnetic field created by the Tayler--Spruit dynamo in differentially rotating stars. Magnetic fields of the order of a few $10^4$ G are present through most of the stellar envelope, with the exception of the…
The lower solar atmosphere consists of partially ionized turbulent plasmas harbouring velocity field, magnetic field and current density fluctuations. The correlations amongst these small scale fluctuations give rise to large scale flows…
Angular momentum has recently been defined as a surface integral involving an axial vector and a twist 1-form, which measures the twisting around of space-time due to a rotating mass. The axial vector is chosen to be a transverse,…
To better understand the observed distributions of rotation rate and magnetic activity of sun-like and low-mass stars, we derive a physically motivated scaling for the dependence of the stellar-wind torque on Rossby number. The torque also…
Stars between two and three solar masses rotate rapidly on the main sequence, and the detection of slow core and surface rotation in the core-helium burning phase for these stars places strong constraints on their angular momentum transport…
The exact location of the solar dynamo remains uncertain--whether it operates primarily in the near-surface shear layer, throughout the entire convection zone, or near the tachocline, a region of sharp transition in the solar rotation,…
We investigate the confinement and long-term dynamics of the magnetised solar tachocline. Starting from first principles, we derive the values of turbulent transport coefficients and then explore the implications for the confinement and…
The early pre-main sequence phase during which they are still likely surrounded by an accretion disk represents a puzzling stage of the rotational evolution of solar-mass stars. While they are still accreting and contracting they do not…
A model is presented that explains the `torsional oscillation' pattern of deviations in the solar rotation rate as a geostrophic flow. The flow is driven by temperature variations near the surface due to the enhanced emission of radiation…
A large drift in the rotation rate of Titan observed by Cassini provided the first evidence of a subsurface ocean isolating the massive core from the icy crust. Seasonal exchange of angular momentum between the surface and atmosphere…
We examine the angular momentum loss and associated rotational spin-down for magnetic hot stars with a line-driven stellar wind and a rotation-aligned dipole magnetic field. Our analysis here is based on our previous 2-D numerical MHD…
Photospheric radiation momentum is efficiently transferred by absorption through metal lines to the gaseous matter in the atmospheres of massive stars, sustaining strong winds and mass loss rates. Not only is this critical for the evolution…
The structure of a star's coronal magnetic field is a fundamental property that governs the high-energy emission from the hot coronal gas and the loss of mass and angular momentum in the stellar wind. It is, however, extremely difficult to…
It has been known for some time now that rapidly-rotating solar-like stars possess the stellar equivalent of solar prominences. These may be three orders of magnitude more massive than their solar counterparts, and their ejection from the…
Overshooting occurs in stars when convective elements penetrate into adjacent radiative zones. In the Sun, it leads to the so-called `tachocline' at the base of the outer convection zone and this region is becoming a key ingredient of the…
In the solar convection zone, rotation couples with intensely turbulent convection to drive a strong differential rotation and achieve complex magnetic dynamo action. Our sun must have rotated more rapidly in its past, as is suggested by…