Self-Consistent Magnetic Stellar Evolution Models of the Detached, Solar-Type Eclipsing Binary EF Aquarii
arXiv:1210.6177 · doi:10.1088/0004-637X/761/1/30
Abstract
We introduce a new one-dimensional stellar evolution code, based on the existing Dartmouth code, that self-consistently accounts for the presence of a globally pervasive magnetic field. The methods involved in perturbing the equations of stellar structure, the equation of state, and the mixing-length theory of convection are presented and discussed. As a first test of the code's viability, stellar evolution models are computed for the components of a solar-type, detached eclipsing binary (DEB) system, EF Aquarii, shown to exhibit large disagreements with stellar models. The addition of the magnetic perturbation corrects the radius and effective temperature discrepancies observed in EF Aquarii. Furthermore, the required magnetic field strength at the model photosphere is within a factor of two of the magnetic field strengths estimated from the stellar X-ray luminosities measured by ROSAT and those predicted from Ca II K line core emission. These models provide firm evidence that the suppression of thermal convection arising from the presence of a magnetic field is sufficient to significantly alter the structure of solar-type stars, producing noticeably inflated radii and cooler effective temperatures. The inclusion of magnetic effects within a stellar evolution model has a wide range of applications, from DEBs and exoplanet host stars to the donor stars of cataclysmic variables.
Accepted for publication in ApJ, 15 pages, 3 figures; Misprints are corrected in version 2
References in corpus (13)
- The Dartmouth Stellar Evolution Database
- The Magnetic Fields of Classical T Tauri Stars
- Evolution of low-mass star and brown dwarf eclipsing binaries
- Simulations of dynamo action in fully convective stars
- KOI-126: A Triply-Eclipsing Hierarchical Triple with Two Low-Mass Stars
- Absolute properties of the low-mass eclipsing binary CM Draconis
- The effect of activity on stellar temperatures and radii
- First Results from the CHARA Array. IV. The Interferometric Radii of Low-Mass Stars
- On the magnetic topology of partially and fully convective stars
- Reevaluating the Mass-Radius Relation for Low-Mass, Main Sequence Stars
- The transiting exoplanet host star GJ 436: a test of stellar evolution models in the lower main sequence, and revised planetary parameters
- The SDSS-HET Survey of Kepler Eclipsing Binaries: Spectroscopic Dynamical Masses of the Kepler-16 Circumbinary Planet Hosts
- Absolute dimensions of solar-type eclipsing binaries. EF Aquarii: a G0 test for stellar evolution models