Stability of the toroidal magnetic field in stellar radiation zones

TL;DR

This paper investigates the stability of toroidal magnetic fields in stellar radiation zones using linear analysis, revealing that gravity cannot fully suppress current-driven instabilities despite stabilizing effects.

Contribution

It provides a detailed linear stability analysis of toroidal magnetic fields in stellar radiation zones, including thermal conductivity effects, which was not comprehensively addressed before.

Findings

Gravity cannot fully suppress magnetic instabilities.

Stable stratification reduces the growth rate of instabilities.

Thermal conductivity influences the stability properties.

Abstract

Understanding the stability of the magnetic field in radiation zones is of crucial importance for various processes in stellar interior like mixing, circulation and angular momentum transport. The stability properties of a star containing a prominent toroidal field in a radiation zone is investigated by means of a linear stability analysis in the Boussinesq approximation taking into account the effect of thermal conductivity. The growth rate of the instability is explicitly calculated and the effects of stable stratification and heat transport are discussed in detail. It is argued that the stabilizing influence of gravity can never entirely suppress the instability caused by electric currents in radiation zones although the stable stratification can significantly decrease the growth rate of instability