by
Gregory A. Feiden(Dartmouth College, USA, and Uppsala Univ.)
→
Europe/Stockholm
122:026
122:026
Description
Low-mass stars are the most populous objects in the galaxy, comprising
nearly 75% of the stellar population. Despite their abundance, studies of
low-mass detached eclipsing binaries (DEBs) have now firmly indicated that
stellar evolution models are unable to accurately predict fundamental
low-mass stellar properties (i.e., radius and effective temperature).
Considering that most known DEBs have short orbital periods, magnetic
activity has been put forth as the leading hypothesis underlying the
observed inflated radii and suppressed temperatures.
In this talk, I will highlight the current effort to develop a new 1-
dimensional stellar evolution code that self-consistently accounts for the
effects of a globally pervasive magnetic field. We find that magnetic
perturbations are able to correct the observed radius and effective
temperature disagreements. Furthermore, the magnetic field strength
required at the model photosphere is within a factor of two of magnetic
field strengths indirectly estimated from X-ray and Ca II emission scaling
relations. Our models provide evidence that the suppression of thermal
convection arising from the presence of a magnetic field is sufficient to
significantly alter the structure of stars with thin convective envelopes.
Finally, the future direction of our efforts and their impact on other
investigations involving low-mass stars, including transiting exoplanet
surveys targeting M-dwarfs, will be mentioned.
