Mullan, D. J.

Contact Email: mullan@bartol.udel.edu
Institute: University of Delaware
First Coauthor: J. MacDonald
Institute: University of Delaware
Subject Area: Stellar Evolution
Waveband: Other (Please Specify Below)
Technique: Computational Astrophysics
Other: none
Presentation: Poster Display
Title: Are magnetically active M dwarfs completely convective?
Abstract: Stars on the main sequence are expected to be completely convective if their mass lies below a certain value, M_cc. Standard stellar structure codes suggest that M_cc is in the range (0.3-0.4)$M_{\odot}$. We examine several non-standard additions to stellar structure in order to quantify their effects on the value of M_cc. We find that by including magnetic field effects, M_cc may fall to values that are significantly smaller than the standard range. This result is of interest in understanding why coronae and chromospheres in active M dwarfs fail to exhibit detectable alterations at spectral class M3-M4. The structural properties of our magnetic models also explain why active M dwarfs tend to have radii that are larger than expected for their T_eff values, or T_eff values that are too low for their radii. Our results lead us to predict that certain stars which are classified as late L or T stars may actually have masses of (0.1-0.15)$M_{\odot}$.