On Chromospheric Variations Modeling for Main-Sequence Stars of G and K Spectral Classes

TL;DR

This paper introduces a method to simulate chromospheric flux variations in G and K main-sequence stars, using solar and stellar data, revealing active region coverage and modeling effectiveness.

Contribution

It presents a chromospheric flux simulation method for Sun-like stars based on HK emission data, extending solar modeling to other stars.

Findings

Solar three-component model explains stellar observations well.

10-20% of K-star surfaces are covered by bright active regions.

The method accurately predicts cyclic flux variations.

Abstract

We present a method of chromospheric flux simulation for 13 late-type main-sequence stars. These Sun-like stars have well-determined cyclic flux variations similar to 11 yr solar activity cycle. Our flux prediction is based on chromospheric HK emission time series measurements from Mount Wilson Observatory and comparable solar data. We show that solar three - component modeling explains well the stellar observations. We find that the 10 - 20% of K - stars disc surfaces are occupied by bright active regions.