The winds of young Solar-type stars in the Hyades

TL;DR

This study models stellar winds of five young Solar-type stars in the Hyades, revealing significantly higher mass and angular momentum loss rates compared to the Sun, with implications for stellar evolution and planetary habitability.

Contribution

It provides the first 3D stellar wind models for Hyades stars using Zeeman-Doppler magnetograms and explores the effects of magnetic field scaling on wind properties.

Findings

Mass loss rates are 2-4 times solar for unscaled fields.

Angular momentum loss is 2-10 times solar for unscaled fields.

Evidence of mass loss saturation at about 10 times solar mass loss rate.

Abstract

Stellar winds govern the spin-down of Solar-type stars as they age, and play an important role in determining planetary habitability, as powerful winds can lead to atmospheric erosion. We calculate three-dimensional stellar wind models for five young Solar-type stars in the Hyades cluster, using TOUPIES survey stellar magnetograms and state-of-the-art Alfv\'en wave driven wind modelling. The stars have the same 0.6-Gyr age and similar fundamental parameters, and we account for the uncertainty in and underestimation of absolute field strength inherent in Zeeman-Doppler imaging by adopting both unscaled and scaled (by a factor of five) field strengths. For the unscaled fields, the resulting stellar wind mass loss is 2-4 times greater and the angular momentum loss 2-10 times greater than for the Sun today, with the scaled results correspondingly greater. We compare our results with a range published of wind models and for the Alfv\'en wave driven modelling see evidence of mass loss saturation at about $10 \dot M_\odot$.