AAS 205th Meeting, 9-13 January 2005
Session 114 Studies of Variable and Moving Objects with the SDSS
Poster, Wednesday, January 12, 2005, 9:20am-6:30pm, Exhibit Hall

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[114.02] Thin Disk Dynamical Heating and the Activity of Low Mass Dwarfs

N. M. Silvestri, A. A. West, S. L. Hawley (Univ. of Washington), K. Cruz (AMNH), I. N. Reid (STScI), J. W. Liebert (Univ. of Arizona/ Steward Obs.)

We present a continuing analysis of the magnetic activity of thousands of M-dwarfs from the Sloan Digital Sky Survey (SDSS) and 2MASS. We confirm the trend described by West et al. (2004) that the fraction of active stars decreases as a function of vertical distance from the galactic plane. This result suggests that the older stars, which have undergone more dynamical heating, are also less likely to remain active, a further confirmation of an age-activity relation. We also investigate a possible variation in the amount of activity (as measured by LH-alpha/Lbol) as a function of distance from the plane and find that there is no statistically significant trend. These data imply that older stars continue to have the same distribution of activity until they cease being active.

The author(s) of this abstract have provided an email address for comments about the abstract: west@astro.washington.edu

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Bulletin of the American Astronomical Society, 36 5
© 2004. The American Astronomical Society.