## Abstract

Our theoretical and numerical analysis have suggested that for low-mass main sequences stars (of the spectral classes from M5 to G0) rotating much faster than the Sun, the generated large-scale magnetic field is caused by the mean-field α^{2} dynamo, whereby the α^{2} dynamo is modified by a weak differential rotation. Even for a weak differential rotation, the behaviour of the magnetic activity is changed drastically from aperiodic regime to non-linear oscillations and appearance of a chaotic behaviour with increase of the differential rotation. Periods of the magnetic cycles decrease with increase of the differential rotation, and they vary from tens to thousand years. This long-term behaviour of the magnetic cycles may be related to the characteristic time of the evolution of the magnetic helicity density of the small-scale field. The performed analysis is based on the mean-field simulations (MFS) of the α^{2} and α^{2} dynamos and a developed non-linear theory of α^{2} dynamo. The applied MFS model was calibrated using turbulent parameters typical for the solar convective zone.

Original language | English |
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Pages (from-to) | 1601-1612 |

Number of pages | 12 |

Journal | Monthly Notices of the Royal Astronomical Society |

Volume | 526 |

Issue number | 2 |

DOIs | |

State | Published - 1 Dec 2023 |

## Keywords

- MHD
- dynamo
- stars: low-mass
- stars: magnetic fields
- turbulence

## ASJC Scopus subject areas

- Astronomy and Astrophysics
- Space and Planetary Science