Related papers: Exploring hydrodynamical stellar tachoclines along…
The property of inhomogeneous turbulence in conducting fluids to expel large-scale magnetic fields in the direction of decreasing turbulence intensity is shown as important for the magnetic field dynamics near the base of a stellar…
Helioseismic inversions of the Sun's internal angular velocity profile show that the rotation changes from differential in latitude in the convection zone to almost uniform in the radiative region below. The transition occurs in a thin…
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 present a fully nonlinear hydrodynamic 'shallow water' model of the solar tachocline. The model consists of a global spherical shell of differentially rotating fluid, which has a deformable top, thus allowing motions in radial directions…
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…
We present the results of three-dimensional simulations of the deep convective envelope of a young (10 Myr) one-solar-mass star, obtained with the Anelastic Spherical Harmonic code. Since young stars are known to be faster rotators than…
We investigate the rotational evolution of solar-like stars with a focus on the internal angular momentum transport processes. The double zone model, in which the star's radiative core and convective envelope are assumed to rotate as solid…
Our ability to predict the structure and evolution of stars is in part limited by complex, 3D hydrodynamic processes such as convective boundary mixing. Hydrodynamic simulations help us understand the dynamics of stellar convection and…
Turbulent motions in the interior of a star play an important role in its evolution, since they transport chemical species, thermal energy and angular momentum. Our overall goal is to construct a practical turbulent closure model for…
Stars of sufficiently low mass are convective throughout their interiors, and so do not possess an internal boundary layer akin to the solar tachocline. Because that interface figures so prominently in many theories of the solar magnetic…
The tachocline is believed to be the region where the solar dynamo operates. With over a solar cycle's worth of data available from the MDI and GONG instruments, we are in a position to investigate not merely the average structure of the…
Since 1995, more than 1500 exoplanets have been discovered around a large diversity of host stars (from M- to A-type stars). Tidal dissipation in stellar convective envelopes is a key actor that shapes the orbital architecture of…
We investigate the relations between tachocline-based dynamos and the surface flux transport mechanisms in stars with outer convection zones. Using our combined models of flux generation and transport, we demonstrate the importance of the…
In solar-type stars (with radiative cores and convective envelopes), the magnetic field powers star spots, flares and other solar phenomena, as well as chromospheric and coronal emission at ultraviolet to X-ray wavelengths. The dynamo…
Stars on the lower main sequence (F-type through M-type) have substantial convective envelopes beneath their stellar photospheres. Convection in these regions can couple with rotation to build global-scale structures that may be observable…
In the solar convection zone, rotation couples with intensely turbulent convection to build global-scale flows of differential rotation and meridional circulation. Our sun must have rotated more rapidly in its past, as is suggested by…
We seek to characterize how the change of global rotation rate influences the overall dynamics and large scale flows arising in the convective envelopes of stars covering stellar spectral types from early G to late K. We do so through…
Overshooting of turbulent motions from convective regions into adjacent stably stratified zones plays a significant role in stellar interior dynamics as this process may lead to mixing of chemical species, and contribute to the transport of…
Time-dependent meridional circulation and differential rotation in radiative zones are central open issues in stellar evolution theory. We streamline this challenging problem using the downward control principle of atmospheric science,…
This paper reports positive detections of surface differential rotation on two rapidly rotating cool stars at several epochs, by using stellar surface features (both cool spots and magnetic regions) as tracers of the large scale latitudinal…