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Related papers: Global simulations of stellar dynamos

200 papers

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 2010-11-15 Benjamin P. Brown , Matthew K. Browning , Allen Sacha Brun , Mark S. Miesch , Juri Toomre

Numerical MHD simulations play increasingly important role for understanding mechanisms of stellar magnetism. We present simulations of convection and dynamos in density-stratified rotating spherical fluid shells. We employ a new 3D…

Solar and Stellar Astrophysics · Physics 2015-09-03 Radostin D. Simitev , Alexander G. Kosovichev , Friedrich H. Busse

To understand solar and stellar dynamos combining local and global numerical modelling with long-term observations is a challenging task: even with state of the art computational methods and resources, the stellar parameter regime remains…

Solar and Stellar Astrophysics · Physics 2021-02-08 M. Viviani , A. Prabhu , J. Warnecke , L. Duarte , J. Pekkilä , M. Rheinhardt , M. J. Käpylä

Magnetic activity is a ubiquitous feature of stars with convective outer layers, with implications from stellar evolution to planetary atmospheres. Investigating the mechanisms responsible for the observed stellar activity signals from days…

Solar and Stellar Astrophysics · Physics 2023-10-17 Emre Işık , Jennifer L. van Saders , Ansgar Reiners , Travis S. Metcalfe

We quantify possible differences between turbulent dynamo action in the Sun and the dynamo action studied in idealized simulations. For this purpose we compare Fourier-space shell-to-shell energy transfer rates of three incrementally more…

Solar and Stellar Astrophysics · Physics 2011-07-08 R. Moll , J. Pietarila Graham , J. Pratt , R. H. Cameron , W. -C. Müller , M. Schüssler

Recent progress in the theory of solar and stellar dynamos is reviewed. Particular emphasis is placed on the mean-field theory which tries to describe the collective behavior of the magnetic field. In order to understand solar and stellar…

Astrophysics · Physics 2009-11-07 Axel Brandenburg , Wolfgang Dobler

Several solar-like stars exhibit cyclic magnetic activity similar to the Sun as found in photospheric and chromospheric emission. We want to understand the physical mechanism involved in rotational dependence of these activity cycle…

Solar and Stellar Astrophysics · Physics 2018-08-22 Jörn Warnecke

The operation of the solar dynamo, with all of its remarkable spatio-temporal ordering, remains an outstanding problem of modern solar physics. A number of mechanisms that might plausibly contribute to its operation have been proposed, but…

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

Recent advances in mean-field theory are reviewed and applications to the Sun, late-type stars, accretion disks, galaxies, and the early Universe are discussed. We focus particularly on aspects of spatio-temporal nonlocality, which is one…

Fluid Dynamics · Physics 2019-01-14 Axel Brandenburg

The theory of the solar/stellar activity cycles is presented, based on the mean-field concept in magnetohydrodynamics. A new approach to the formulation of the electromotive force and the theory of differential rotation and meridional…

Astrophysics · Physics 2017-02-22 Günther Rüdiger , Rainer Arlt

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

The role of turbulent effects for dynamos in the Sun and stars continues to be debated. Mean-field (MF) theory provides a broadly used framework to connect these effects to fundamental magnetohydrodynamics. While inaccessible…

Solar and Stellar Astrophysics · Physics 2021-10-06 Jörn Warnecke , Matthias Rheinhardt , Mariangela Viviani , Frederick Gent , Simo Tuomisto , Maarit J. Käpylä

Convective turbulent motions in the solar interior, as well as the mean flows resulting from them, determine the evolution of the solar magnetic field. With the aim to get a better understanding of these flows we study anelastic rotating…

Solar and Stellar Astrophysics · Physics 2015-06-12 G. Guerrero , P. K. Smolarkiewicz , A. Kosovichev , N. Mansour

An overview is given about recent developments and results of comprehensive simulations of magneto-convective processes in the near-surface layers and photosphere of the Sun. Simulations now cover a wide range of phenomena, from whole…

Solar and Stellar Astrophysics · Physics 2015-06-12 Manfred Schüssler

The periods of magnetic activity cycles in the Sun and solar-type stars do not exhibit a simple or even single trend with respect to rotation rate or luminosity. Dynamo models can be used to interpret this diversity, and can ultimately help…

Solar and Stellar Astrophysics · Physics 2018-08-15 A. Strugarek , P. Beaudoin , P. Charbonneau , A. S. Brun

A brief summary of the various observations and constraints that underlie solar dynamo research are presented. The arguments that indicate that the solar dynamo is an alpha-omega dynamo of the Babcock-Leighton type are then shortly…

Solar and Stellar Astrophysics · Physics 2017-09-26 R. H. Cameron , M. Dikpati , A. Brandenburg

The magnetic activity of the Sun, as manifested in the sunspot cycle, originates deep within its convection zone through a dynamo mechanism which involves non-trivial interactions between the plasma and magnetic field in the solar interior.…

Solar and Stellar Astrophysics · Physics 2015-05-13 Dibyendu Nandy

In this paper, written as a general historical and technical introduction to the various review papers collected in the special issue ``Solar and Stellar Dynamo: A New Era'', we review the evolution and current state of dynamo theory and…

Solar and Stellar Astrophysics · Physics 2023-07-05 Paul Charbonneau , Dmitry Sokoloff

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…