Evolution of Solar-Type Activity: An Observational and Theoretical Perspective

TL;DR

This paper reviews observational and theoretical insights into how solar-type stellar activity evolves as stars leave the main sequence, focusing on changes in magnetic activity, stellar winds, and atmospheric emissions, with Beta Hydri as a key example.

Contribution

It provides a comprehensive summary of recent observational and theoretical studies on the evolution of solar-type activity, highlighting new findings for stars like Beta Hydri.

Findings

Stellar angular momentum loss impacts activity levels.

Changes in UV and X-ray emissions correlate with stellar evolution.

Theoretical models explain magnetic and acoustic energy variations.

Abstract

When stars depart from the main-sequence, various changes occur including the loss of angular momentum owing to changes in the stellar interior and the impact of stellar winds. These processes affect the amount of outer atmospheric heating and emission as revealed by observations in the UV and X-ray spectral regimes. From a theoretical perspective, both magnetic and acoustic energy generation are affected as indicated by detailed theoretical simulations. Here, I will summarize selected observational and theoretical results, including recent work for Beta Hydri (G2~IV), a star constituting a prime example and proxy for the future Sun.