Stellar Evolution with Rotation and Magnetic Fields IV: The Solar Rotation Profile

TL;DR

This paper investigates how magnetic fields influence the internal rotation profile of solar-like stars, showing that magnetic coupling and circulation lead to an equilibrium close to solid body rotation, consistent with helioseismic data.

Contribution

It introduces a model for the evolution of stellar rotation profiles considering magnetic effects, providing insights into the balance between magnetic coupling and circulation.

Findings

The equilibrium rotation profile is close to solid body rotation between 0.7 and 0.2 R_sun.

Magnetic coupling favors uniform rotation, while meridional circulation promotes differential rotation.

The model aligns well with helioseismic measurements of the solar interior.

Abstract

We examine the generation of a magnetic field in a solar-like star and its effects on the internal distribution of the angular velocity. We suggest that the evolution of a rotating star with magnetic fields leads to an equilibrium value of the differential rotation. This equilibrium is determined by the magnetic coupling, which favours a constant rotation profile, and meridional circulation which tends to build differential rotation. The global equilibrium stage is close to solid body rotation between about 0.7 and 0.2 R_sun, in good agreement with helioseismic measurements.