The Sun and other stars are magnetic: magnetism pervades their interiors and affects their
evolution in a variety of ways. In the Sun, both the fields themselves and their influence on …

The Sun's magnetic field is the engine and energy source driving all phenomena collectively
defining solar activity, which in turn structures the whole heliosphere and significantly …

These lecture notes are based on a tutorial given in 2017 at a plasma physics winter school
in Les Houches. Their aim is to provide a self-contained graduate-student level introduction …

We present here the final results of the first spectropolarimetric survey of a small sample of
active M dwarfs, aimed at providing observational constraints on dynamo action on both …

Stellar wind is thought to be the main process responsible for the spin down of main-
sequence stars. The extraction of angular momentum by a magnetized wind has been …

We use the anelastic spherical harmonic code to model the convective dynamo of solar-type
stars. Based on a series of 15 3D MHD simulations spanning four bins in rotation and mass …

This paper reviews recent advances and current debates in modeling the solar cycle as a
hydromagnetic dynamo process. Emphasis is placed on (relatively) simple dynamo models …

Aims. Although the time of the Maunder minimum (1645–1715) is widely known as a period
of extremely low solar activity, it is still being debated whether solar activity during that …

We review the state of the art of three dimensional numerical simulations of solar and stellar
dynamos. We summarize fundamental constraints of numerical modelling and the …

The observational absence of giant convection cells near the Sun's outer surface is a long-
standing conundrum for solar modelers. We herein propose an explanation. Rotation …