Precision modeling of M dwarf stars: the magnetic components of CM Draconis

TL;DR

This paper investigates the discrepancies between observed and modeled properties of the M dwarf binary CM Draconis, focusing on magnetic effects, to improve understanding of low-mass stellar physics.

Contribution

It introduces a magnetic component into stellar models to better match the observed properties of CM Draconis's components.

Findings

Standard models underestimate stellar radii by several standard deviations.

Magnetic models better reproduce observed radii and luminosities.

Results suggest magnetic activity significantly influences M dwarf structure.

Abstract

The eclipsing binary CM Dra contains nearly identical red dwarfs of spectral class dM4.5. Their masses and radii have been reported with unprecedentedly small statistical errors. When compared with standard stellar models of appropriate age (\approx4 Gyr), the empirical results indicate that both components are larger in R, and lower in luminosity L, by several standard deviations. Here, we attempt at first to model the components in the context of standard stellar models using differ