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C. M. Johns-Krull (Rice University), J. A. Valenti (Space Telescope Science Institute)
We present high resolution K band spectra obtained with CSHELL on the NASA Infrared Telescope Facility of 15 classical T Tauri stars in order to test models of magnetospheric accretion and disk locking in these young stars. The stellar parameters (mass, radius, rotation period) and mass acretion rates for each star are already known so that we can use disk locking theory to predict the magnetic field strength at the surface of each star. Magnetically sensitive lines in our K band spectra show obvious excess broadening relative to magnetically insensitive lines. We use these lines to measure mean magnetic field strengths for each star in the sample. We find no significant correlation between the observed mean fields and the field strengths predicted by disk locking theory. We discuss possible reaons for the apparent failure of the theory, the most likely of which is that the field geometry on the stellar surface is not a dipole as generally assumed in the theory. We will also discuss the X-ray properties of our stars in relation to their magnetic field strengths.
This research was funded in part through a NASA Origins of Solar Systems grant to William Marsh Rice University.
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Bulletin of the American Astronomical Society, 37 #4
© 2005. The American Astronomical Soceity.