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Related papers: Granulation and Convectional Driving on Stellar Su…

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We propose collisionless damping of fast MHD waves as an important mechanism for the heating and acceleration of winds from rotating stars. Stellar rotation causes magnetic field lines anchored at the surface to form a spiral pattern and…

Astrophysics · Physics 2009-11-24 T. K. Suzuki , H. Yan , A. Lazarian , J. P. Cassinelli

This article reviews our current understanding of modelling convection dynamics in stars. Several semi-analytical time-dependent convection models have been proposed for pulsating one-dimensional stellar structures with different…

Solar and Stellar Astrophysics · Physics 2016-01-18 Günter Houdek , Marc-Antoine Dupret

Magnetohydrodynamic star-in-a-box simulations of convection and dynamos in a solar-like star with different rotation rates are presented. These simulations produce solar-like differential rotation with a fast equator and slow poles, and…

Solar and Stellar Astrophysics · Physics 2022-06-08 Petri J. Käpylä

Despite the lack of a shear-rich tachocline region low-mass fully convective stars are capable of generating strong magnetic fields, indicating that a dynamo mechanism fundamentally different from the solar dynamo is at work in these…

Solar and Stellar Astrophysics · Physics 2015-11-11 Rakesh K. Yadav , Ulrich R. Christensen , Julien Morin , Thomas Gastine , Ansgar Reiners , Katja Poppenhaeger , Scott J. Wolk

For Sun-like stars, the generation of toroidal magnetic field from poloidal magnetic field is an essential piece of the dynamo mechanism powering their magnetism. Previous authors have estimated the net toroidal flux generated in each…

Solar and Stellar Astrophysics · Physics 2024-01-23 Adam J. Finley , Sacha A. Brun , Antoine Strugarek , Robert Cameron

We report the results of a magneto-hydrodynamic (MHD) simulation of a convective dynamo in a model solar convective envelope driven by the solar radiative diffusive heat flux. The convective dynamo produces a large-scale mean magnetic field…

Solar and Stellar Astrophysics · Physics 2014-06-18 Yuhong Fan , Fang Fang

The advent of massively parallel supercomputing has begun to permit explicit 3--D simulations of turbulent convection occurring within the cores of early-type main sequence stars. Such studies should complement the stellar structure and…

Astrophysics · Physics 2007-05-23 Allan Sacha Brun , Matthew Browning , Juri Toomre

A number of observational and theoretical aspects of solar magnetoconvection are considered in this review. We discuss recent developments in our understanding of the small-scale structure of the magnetic field on the solar surface and its…

Solar and Stellar Astrophysics · Physics 2015-12-29 J. M. Borrero , S. Jafarzadeh , M. Schüssler , S. K. Solanki

Stellar magnetic activity of solar like stars is thought to be due to an internal dynamo. While the Sun has been the subject of intense research for refining dynamo models, observations of magnetic cyclic activity in solar type stars have…

Solar and Stellar Astrophysics · Physics 2015-06-03 Olivier Do Cao , Allan Sacha Brun

We report on a mechanism which may lead to a spin-up of the surface of a rotating single star leaving the Hayashi line, which is much stronger than the spin-up expected from the mere contraction of the star. By analyzing rigidly rotating,…

Astrophysics · Physics 2007-05-23 Alexander Heger , Norbert Langer

Astronomical observation of stellar rotation suggests that at least the surface layers of the Sun have lost a substantial amount of the angular momentum that they possessed at the beginning of the main-sequence phase of evolution; and…

Solar and Stellar Astrophysics · Physics 2015-05-13 D. O. Gough

We carry out a magneto-hydrodynamic (MHD) simulation of convective dynamo in the rotating solar convective envelope driven by the solar radiative diffusive heat flux. The simulation is similar to that reported in Fan & Fang (2014) but with…

Solar and Stellar Astrophysics · Physics 2016-01-12 Yuhong Fan , Fang Fang

Usual explanations of spiral galaxy rotation curves assume circular orbits of stars. The consequences of giving up this assumption are investigated here. In particular, hyperbolic stellar trajectories are found to be interesting. The two…

Astrophysics of Galaxies · Physics 2018-01-30 Tarun Biswas

Stars form by the gravitational collapse of interstellar gas. The thermodynamic response of the gas can be characterized by an effective equation of state. It determines how gas heats up or cools as it gets compressed, and hence plays a key…

A region of a star that is stable to convection according to the Ledoux criterion may nevertheless undergo additional mixing if the mean molecular weight increases with radius. This process is called fingering (thermohaline) convection and…

Solar and Stellar Astrophysics · Physics 2013-04-16 Justin M. Brown , Pascale Garaud , Stephan Stellmach

Granulates are ubiquitous in nature and technology, but despite their great importance, their dynamics are by far less well understood than those of liquids. We demonstrate in an almost compactly filled flat (Hele-Shaw) cell, where slow…

Soft Condensed Matter · Physics 2017-06-23 Frank Rietz , Ralf Stannarius

Our understanding of stellar dynamos has largely been driven by the phenomena we have observed of our own Sun. Yet, as we amass longer-term datasets for an increasing number of stars, it is clear that there is a wide variety of stellar…

Solar and Stellar Astrophysics · Physics 2019-01-30 Maria A. Weber

Convection is a fundamental physical process in the fluid cores of planets because it is the primary transport mechanism for heat and chemical species and the primary energy source for planetary magnetic fields. Key properties of…

Geophysics · Physics 2019-09-11 Céline Guervilly , Philippe Cardin , Nathanaël Schaeffer

Manifestations of stellar activity (such as star-spots, plage/faculae, and convective flows) are well known to induce spectroscopic signals often referred to as astrophysical noise by exoplanet hunters. For example, setting an ultimate goal…

Solar and Stellar Astrophysics · Physics 2019-03-27 H. M. Cegla , C. A. Watson , S. Shelyag , W. J. Chaplin , G. R. Davies , M. Mathioudakis , M. L. III Palumbo , S. H. Saar , R. D. Haywood

Inner core translation, with solidification on one hemisphere and melting on the other, provides a promising basis for understanding the hemispherical dichotomy of the inner core, as well as the anomalous stable layer observed at the base…

Geophysics · Physics 2015-06-16 Renaud Deguen , Thierry Alboussière , Philippe Cardin