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Related papers: Persistent Magnetic Wreaths in a Rapidly Rotating …

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When our Sun was young it rotated much more rapidly than now. Observations of young, rapidly rotating stars indicate that many possess substantial magnetic activity and strong axisymmetric magnetic fields. We conduct simulations of dynamo…

Solar and Stellar Astrophysics · Physics 2009-06-15 Benjamin P. Brown , Matthew K. Browning , Mark S. Miesch , Allan Sacha Brun , Juri Toomre

When stars like our Sun are young they rotate rapidly and are very magnetically active. We explore dynamo action in rapidly rotating suns with the 3-D MHD anelastic spherical harmonic (ASH) code. The magnetic fields built in these dynamos…

Solar and Stellar Astrophysics · Physics 2015-05-20 Benjamin P Brown , Matthew K Browning , Allan S Brun , Mark S Miesch , Juri Toomre

Solar-type stars exhibit a rich variety of magnetic activity. Seeking to explore the convective origins of this activity, we have carried out a series of global 3D magnetohydrodynamic (MHD) simulations with the anelastic spherical harmonic…

Solar and Stellar Astrophysics · Physics 2015-06-12 Nicholas J. Nelson , Benjamin P. Brown , A. Sacha Brun , Mark S. Miesch , Juri Toomre

Young solar-type stars rotate rapidly and are very magnetically active. The magnetic fields at their surfaces likely originate in their convective envelopes where convection and rotation can drive strong dynamo action. Here we explore…

Solar and Stellar Astrophysics · Physics 2011-01-04 Benjamin P Brown , Matthew K Browning , Allan Sacha Brun , Mark S Miesch , Juri Toomre

Young solar-type stars rotate rapidly and many are magnetically active; some undergo magnetic cycles similar to the 22-year solar activity cycle. We conduct simulations of dynamo action in rapidly rotating suns with the 3D MHD anelastic…

Solar and Stellar Astrophysics · Physics 2011-03-28 Benjamin P. Brown , Mark S. Miesch , Matthew K. Browning , Allen Sacha Brun , Juri Toomre

The operation of the solar global dynamo appears to involve many dynamical elements. Self-consistent MHD simulations which realistically incorporate all of these processes are not yet computationally feasible, though some elements can now…

Astrophysics · Physics 2008-11-26 Allan Sacha Brun , Mark S. Miesch , Juri Toomre

Our global 3D simulations of convection and dynamo action in a Sun-like star reveal that persistent wreaths of strong magnetism can be built within the bulk of the convention zone. Here we examine the characteristics of buoyant magnetic…

Solar and Stellar Astrophysics · Physics 2015-06-12 Nicholas J. Nelson , Benjamin P. Brown , A. Sacha Brun , Mark S. Miesch , Juri Toomre

Stellar dynamos are driven by complex couplings between rotation and turbulent convection, which drive global-scale flows and build and rebuild stellar magnetic fields. When stars like our sun are young, they rotate much more rapidly than…

Our Sun exhibits strong convective dynamo action which results in magnetic flux bundles emerging through the stellar surface as magnetic spots. Global-scale dynamo action is believed to generate large-scale magnetic structures in the deep…

Solar and Stellar Astrophysics · Physics 2014-03-05 Nicholas J. Nelson , Mark S. Miesch

We discuss recent advances made in modelling the complex magnetohydrodynamics of the Sun using our anelastic spherical harmonics (ASH) code. We have conducted extensive 3--D simulations of compressible convection in rotating spherical…

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

We live near a magnetic star whose cycles of activity are driven by dynamo action beneath the surface. In the solar convection zone, rotation couples with plasma motions to build highly organized magnetic fields that erupt at the surface…

Solar and Stellar Astrophysics · Physics 2015-05-20 Benjamin P Brown

Observations of sun-like stars rotating faster than our current sun tend to exhibit increased magnetic activity as well as magnetic cycles spanning multiple years. Using global simulations in spherical shells to study the coupling of…

Solar and Stellar Astrophysics · Physics 2015-05-20 Nicholas J. Nelson , Benjamin P. Brown , Matthew K. Browning , Allan Sacha Brun , Mark S. Miesch , Juri Toomre

The current dynamo paradigm for the Sun and sun-like stars places the generation site for strong toroidal magnetic structures deep in the solar interior. Sunspots and star-spots on sun-like stars are believed to arise when sections of these…

Solar and Stellar Astrophysics · Physics 2015-05-30 Nicholas J. Nelson , Benjamin P. Brown , Allan Sacha Brun , Mark S. Miesch , Juri Toomre

Core convection and dynamo activity deep within rotating A-type stars of 2 solar masses are studied with 3--D nonlinear simulations. Our modeling considers the inner 30% by radius of such stars, thus capturing within a spherical domain the…

Astrophysics · Physics 2008-11-26 Allan Sacha Brun , Matthew K. Browning , Juri Toomre

The global-scale dynamo action achieved in a simulation of a Sun-like star rotating at thrice the solar rate is assessed. The 3-D MHD Anelastic Spherical Harmonic (ASH) code, augmented with a viscosity minimization scheme, is employed to…

Solar and Stellar Astrophysics · Physics 2015-03-17 Kyle Augustson , Sacha Brun , Mark Miesch , Juri Toomre

We review recent advances in modeling global-scale convection and dynamo processes with the Anelastic Spherical Harmonic (ASH) code. In particular, we have recently achieved the first global-scale solar convection simulations that exhibit…

Astrophysics · Physics 2008-11-20 M. S. Miesch , M. K. Browning , A. S. Brun , J. Toomre , B. P. Brown

Many stars exhibit strong magnetic fields, some of which are thought to be of primordial origin and others a sign of magnetic dynamo processes. We briefly review the results of observational studies of solar-type stars seeking to evaluate…

Astrophysics · Physics 2007-05-23 Allan Sacha Brun

Recent observations indicate that fully convective stars can effectively build magnetic fields without the aid of a tachocline of shear, that those fields can possess large-scale components, and that they may sense the effects of rotation.…

Astrophysics · Physics 2009-11-13 Matthew Browning , Gibor Basri

We present the first results from three-dimensional spherical shell simulations of magnetic dynamo action realized by turbulent convection penetrating downward into a tachocline of rotational shear. This permits us to assess several…

Astrophysics · Physics 2011-02-11 Matthew Browning , Mark S. Miesch , Allan Sacha Brun , Juri Toomre

The dynamo action achieved in the convective cores of main-sequence massive stars is explored here through 3D global simulations of convective core dynamos operating within a young $\Msun{10}$ B-type star, using the anelastic spherical…

Solar and Stellar Astrophysics · Physics 2016-10-05 Kyle C. Augustson , Allan Sacha Brun , Juri Toomre
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