The Benchmark Eclipsing Binary V530 Ori: A Critical Test of Magnetic Evolution Models for Low-Mass Stars

TL;DR

This paper presents precise measurements of an eclipsing binary system V530 Ori, revealing discrepancies with standard models for low-mass stars, and demonstrates that magnetic field-inclusive models can better explain observed stellar properties.

Contribution

It provides the first detailed test of magnetic evolution models against accurate measurements of a low-mass star in an eclipsing binary.

Findings

The secondary star has a larger radius and cooler temperature than standard models predict.

Magnetic models with 1-2 kG fields successfully match the observed properties.

Standard models without magnetic effects fail to reproduce the secondary star's characteristics.

Abstract

We report accurate measurements of the physical properties (mass, radius, temperature) of components of the G+M eclipsing binary V530 Ori. The M-type secondary shows a larger radius and a cooler temperature than predicted by standard stellar evolution models, as has been found for many other low-mass stars and ascribed to the effects of magnetic activity and/or spots. We show that models from the Dartmouth series that incorporate magnetic fields are able to match the observations with plausible field strengths of 1-2 kG, consistent with a rough estimate we derive for that star.