Rotating models of young solar-type stars : Exploring braking laws and angular momentum transport processes

TL;DR

This study models the rotational evolution of solar-type stars, testing various physical prescriptions against observational data to identify the most accurate descriptions of angular momentum transport and stellar braking.

Contribution

It introduces a comprehensive set of rotating stellar evolution models exploring different angular momentum transport and braking laws, validated against multiple observational constraints.

Findings

Best-fit prescriptions for internal transport and surface braking match observed rotational evolution.

Fast rotators show stronger coupling between radiative core and convective envelope.

Additional angular momentum transport mechanisms are needed to fully explain solar and stellar observations.

Abstract

We study the predicted rotational evolution of solar-type stars from the pre-main sequence to the solar age with 1D rotating evolutionary models including physical ingredients. We computed rotating evolution models of solar-type stars including an external stellar wind torque and internal transport of angular momentum following the method of Maeder and Zahn with the code STAREVOL. We explored different formalisms and prescriptions available from the literature. We tested the predictions of the models against recent rotational period data from extensive photometric surveys, lithium abundances of solar-mass stars in young clusters, and the helioseismic rotation profile of the Sun. We find a best-matching combination of prescriptions for both internal transport and surface extraction of angular momentum. This combination provides a very good fit to the observed evolution of rotational periods for solar-type stars from early evolution to the age of the Sun. Additionally, we show that fast rotators experience a stronger coupling between their radiative region and the convective envelope. Regardless of the set of prescriptions, however, we cannot simultaneously reproduce surface angular velocity and the internal profile of the Sun or the evolution of lithium abundance. We confirm the idea that additional transport mechanisms must occur in solar-type stars until they reach the age of the Sun. Whether these processes are the same as those needed to explain recent asteroseismic data in more advanced evolutionary phases is still an open question.