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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

The Sun and solar-type stars exhibit irregular cyclic variations in their magnetic activity over long time scales. To understand this irregularity, we employed the flux transport dynamo models to investigate the behavior of one solar mass…

Solar and Stellar Astrophysics · Physics 2024-12-25 Vindya Vashishth

Surface convection is important for the presence of magnetic activity at stars. So far, this convection is thought to be a result of heating from below, where convection cells rise and break up. New models reveal that surface convection is…

Solar and Stellar Astrophysics · Physics 2025-07-16 Johannes Tschernitz , Philippe-A. Bourdin

Sunspots and the plethora of other phenomena occuring in the course of the 11-year cycle of solar activity are a consequence of the emergence of magnetic flux at the solar surface. The observed orientations of bipolar sunspot groups imply…

Solar and Stellar Astrophysics · Physics 2015-06-24 Robert Cameron , Manfred Schüssler

Observations of chromospheric and coronal emissions from various solar-type stars show that the stellar magnetic activity varies with the rotation rates of the stars. The faster the star rotates, its magnetic activity gets stronger but…

Solar and Stellar Astrophysics · Physics 2019-10-16 Gopal Hazra , Jie Jiang , Bidya Binay Karak , Leonid Kitchatinov

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

Aims: We aim to investigate how converging flows towards active regions affect the surface transport of magnetic flux, as well as their impact on the generation of the Sun's poloidal field. The inflows constitute a potential non-linear…

Solar and Stellar Astrophysics · Physics 2016-12-21 David Martin-Belda , Robert H. Cameron

Flux-dominated solar dynamo models have demonstrated to reproduce the main features of the large scale solar magnetic cycle, however the use of a solar like differential rotation profile implies in the the formation of strong toroidal…

Astrophysics · Physics 2009-11-13 G. A. Guerrero , E. M. de G. Dal Pino

The Sun is a magnetic star whose cyclic activity is thought to be linked to internal dynamo mechanisms. A combination of numerical modelling with various levels of complexity is an efficient and accurate tool to investigate such intricate…

Solar and Stellar Astrophysics · Physics 2015-05-19 L. Jouve , M. R. E. Proctor , G. Lesur

Magnetic activity is known to be correlated to the rotation period for moderately active main sequence solar-like stars. In turn, the stellar rotation period evolves as a result of magnetised stellar winds that carry away angular momentum.…

The dynamic activity of stars such as the Sun influences (exo)planetary space environments through modulation of stellar radiation, plasma wind, particle and magnetic fluxes. Energetic stellar phenomena such as flares and coronal mass…

Solar and Stellar Astrophysics · Physics 2023-07-26 Prantika Bhowmik , Jie Jiang , Lisa Upton , Alexandre Lemerle , Dibyendu Nandy

Spectropolarimetric observations show that many low-mass stars possess large-scale poloidal magnetic fields with considerable dipole component, which in some cases exhibit temporal dynamics - cycles or reversals. Although it is widely…

Solar and Stellar Astrophysics · Physics 2025-07-02 Anna Guseva , Ludovic Petitdemange , Charly Pinçon

Meridional flow is crucial in generating the solar poloidal magnetic field by facilitating the poleward transport of the field from the decayed Bipolar Magnetic Regions (BMRs). As the meridional circulation changes with the stellar rotation…

Solar and Stellar Astrophysics · Physics 2024-07-24 Vindya Vashishth , Bidya Binay Karak

Assuming that the torsional oscillation is driven by the Lorentz force of the magnetic field associated with the sunspot cycle, we use a flux transport dynamo to model it and explain its initiation at a high latitude before the beginning of…

Solar and Stellar Astrophysics · Physics 2015-05-19 Piyali Chatterjee , Sagar Chakraborty , Arnab Rai Choudhuri

In G dwarfs, the surface distribution, coverage and lifetimes of starspots deviate from solar-like patterns as the rotation rate increases. We set up a numerical platform which includes the large-scale rotational and surface flow effects,…

Solar and Stellar Astrophysics · Physics 2018-12-24 Emre Işık , Sami K. Solanki , Natalie A. Krivova , Alexander I. Shapiro

We carry out numerical simulations of the surface evolution of bipolar magnetic regions (BMRs) and magnetic spots on stars, which have radii and surface rotational shears of AB Doradus, the Sun, and the HR 1099 primary. The surface flux…

Astrophysics · Physics 2009-11-11 Emre Isik , Manfred Schuessler , Sami K. Solanki

Stars are changing entities in a constant evolution during their lives. At non-secular time scales (from seconds to years) the effect of dynamical processes such as convection, rotation, and magnetic fields can modify the stellar…

Solar and Stellar Astrophysics · Physics 2019-07-09 S. Mathur , J. Ballot , R. A. Garcia

Evidence of surface magnetism is now observed on an increasing number of cool stars. The detailed manner by which dynamo-generated magnetic fields giving rise to starspots traverse the convection zone still remains unclear. Some insight…

Solar and Stellar Astrophysics · Physics 2017-09-20 Maria A. Weber , Matthew K. Browning , Suzannah Boardman , Joshua Clarke , Samuel Pugsley , Edward Townsend

Arguments for and against the widely accepted picture of a solar dynamo being seated in the tachocline are reviewed and alternative ideas concerning dynamos operating in the bulk of the convection zone, or perhaps even in the near-surface…

Astrophysics · Physics 2007-05-23 Axel Brandenburg

We study the pumping of magnetic flux in three-dimensional compressible magnetoconvection in the context of stellar dynamos. The simulation domain represents a rectangular section from the lower part of a stellar convection zone plus the…

Astrophysics · Physics 2009-11-07 M. Ossendrijver , M. Stix , A. Brandenburg , G. Ruediger