Related papers: Evolution of solar and stellar dynamo theory
Simulations of magnetohydrodynamics convection in slowly rotating stars predict anti-solar differential rotation (DR) in which the equator rotates slower than poles. This anti-solar DR in the usual $\alpha \Omega$ dynamo model does not…
We study the cosmic evolution of the magnetic fields of a large sample of spiral galaxies in a cosmologically representative volume by employing a semi-analytic galaxy formation model and numerical dynamo solver in tandem. We start by…
We first discuss how the flux transport dynamo with reasonably high diffusion can explain both the regular and the irregular features of the solar cycle quite well. Then we critically examine the inadequacies of the model and the challenge…
Our understanding of the structure and dynamics of stellar coronae has changed dramatically with the availability of surface maps of both star spots and also magnetic field vectors. Magnetic field extrapolations from these surface maps…
In recent years, the development of spectropolarimetric techniques deeply modified our knowledge of stellar magnetism. In the case of solar-type stars, the challenge is to measure a geometrically complex field and determine its evolution…
Recent findings of helioseismology as well as advances in direct numerical simulations of global dynamics of the Sun have indicated that in each solar hemisphere the meridional circulation forms the two cells along the in the convection…
Magnetic fields can be created in stably stratified (non-convective) layers in a differentially rotating star. A magnetic instability in the toroidal field (wound up by differential rotation) replaces the role of convection in closing the…
Context. The solar dynamo consists of a process that converts poloidal field to toroidal field followed by a process which creates new poloidal field from the toroidal field. Aims. Our aim is to observe the poloidal and toroidal fields…
Magnetohydrodynamic interactions between plasma flows and magnetic fields is fundamental to the origin and sustenance of the 11-year sunspot cycle. These processes are intrinsically three-dimensional (3D) in nature. Our goal is to construct…
Stellar evolution models are a cornerstone of young star astrophysics, which necessitates that they yield accurate and reliable predictions of stellar properties. Here, I review the current performance of stellar evolution models against…
The most widely accepted model of the solar cycle is the flux transport dynamo model. This model evolved out of the traditional $\alpha \Omega$ dynamo model which was first developed at a time when the existence of the Sun's meridional…
The periodically varying Lorentz force of the periodic solar magnetic field generated by the solar dynamo can induce two kinds of motions: torsional oscillations and periodic variations in the meridional circulation. Observational evidence…
In recent years, astronomers have witnessed major progresses in the field of stellar physics. This was made possible thanks to the combination of a solid theoretical understanding of the phenomena of stellar pulsations and the availability…
In this review, we explain recent progress made in the Babcock-Leighton dynamo models for the Sun, which have been most successful to explain various properties of the solar cycle. In general, these models are 2D axisymmetric and the…
The meridional circulation plays an essential role in determining the basic mechanism of the dynamo action in case the of a low eddy diffusivity. Flux-transport dynamos with strong return flow and a deep stagnation point are discussed in…
Regardless of the physical origin of stellar magnetic fields - fossil or dynamo induced - an inclination angle between the magnetic and rotation axes is very often observed. Absence of observational evidence in this direction in the solar…
The origin and maintenance of coherent magnetic fields in the Universe is reviewed with an emphasis on the possible challenges that arise in their theoretical understanding. We begin with the interesting possibility that magnetic fields…
The main aim of this paper is to introduce the most important observables that help us to investigate stellar dynamos and compare those to the modeling results. We give an overview of the available observational methods and data processing…
We construct a magnetic helicity conserving dynamo theory which incorporates a calculated magnetic helicity current. In this model the fluid helicity plays a small role in large scale magnetic field generation. Instead, the dynamo process…
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…