Do Magnetic Fields Actually Inflate Low-Mass Stars?
Abstract
Magnetic fields have been hypothesized to inflate the radii of low-mass stars-defined as less than 0.8 M ⊙-in detached eclipsing binaries (DEBs). We evaluate this hypothesis using the magnetic Dartmouth stellar evolution code. Results suggest that magnetic suppression of thermal convection can inflate low-mass stars that possess a radiative core and convective outer envelope. A scaling relation between X-ray luminosity and surface magnetic flux indicates that model surface magnetic field strength predictions are consistent with observations. This supports the notion that magnetic fields may be inflating these stars. However, magnetic models are unable to reproduce radii of fully convective stars in DEBs. Instead, we propose that model discrepancies below the fully convective boundary are related to metallicity.
- Publication:
-
Magnetic Fields throughout Stellar Evolution
- Pub Date:
- August 2014
- DOI:
- arXiv:
- arXiv:1309.7668
- Bibcode:
- 2014IAUS..302..150F
- Keywords:
-
- binaries: eclipsing;
- stars: evolution;
- stars: interiors;
- stars: low-mass;
- stars: magnetic field;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 4 pages, 3 figures, to appear in proceedings from IAU Symp. 302: "Magnetic Fields Throughout Stellar Evolution"