Coronal Temperature as an Age Indicator

TL;DR

This study demonstrates that coronal temperatures in late-type stars are strongly linked to stellar age, with hot plasma temperature decaying as a power law and cool plasma temperature decreasing linearly with log(age).

Contribution

It establishes a new method to estimate stellar age based on coronal temperature measurements, highlighting different decay behaviors for hot and cool plasma components.

Findings

Hot plasma temperature shows larger scatter and is influenced by stellar activity.

Cool plasma temperature decays linearly with log(age).

Hot plasma temperature follows a power-law decay with age.

Abstract

The X-ray spectra of late type stars can generally be well fitted by a two temperature component model of the corona. We fnd that the temperature of both components are strong functions of stellar age, although the temperature of the hotter plasma in the corona shows a larger scatter and is probably affected by the activity of stars, such as flares. We confirm the power-law decay of the temperature of the hot plasma, but the temperature of the cool component decays linearly with log (age).