Name/Affiliation: Gregory Feiden (Uppsala University)
The Influence of Magnetic Fields on the Structure of Low-Mass Stars
Magnetic fields are increasingly being invoked to explain discrepancies between observations of the fundamental properties of low-mass stars and predictions from stellar evolution models. However, the efficacy of the magnetic field hypothesis remains unclear. Results from different stellar evolution codes that include effects of magnetic fields agree about the properties of magnetic fields required to relieve the observed discrepancies. But, there are differing interpretations about whether the required magnetic properties are physically plausible. Star spots have also been invoked to explain the same phenomena, but they, too, skirt the realm of what is thought to be physically realistic. In this talk, I will review the current evidence for and against the hypothesis that magnetic fields are strongly impacting the structure of low-mass stars. Emphasis will be placed on results obtained using so-called "magnetic" stellar evolution models that have been used to explain discrepancies in low-mass eclipsing binaries, young stellar associations, and relatively young open clusters. Along the way, I will attempt to take seemingly disparate and contradictory pieces of evidence and form them into a cohesive picture of how magnetic fields are influencing the structure of low-mass stars.