AAS 205th Meeting, 9-13 January 2005
Session 55 M dwarfs, Nearby Stars and High-proper-motion Stars
Poster, Tuesday, January 11, 2005, 9:20am-6:30pm, Exhibit Hall

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[55.07] The Quiescent Atmosphere of the dMe Flare Star EV Lacertae

R. A. Osten (NRAO), S. L. Hawley (U. of Washington), C. M. Johns-Krull (Rice University), A. Brown (U. of Colorado), J. Allred (U. of Washington)

We report on multi-wavelength spectroscopic observations of the M dwarf flare star, EV Lacertae, during quiescent intervals. The study of extreme coronae, such as on M dwarf flare stars, allows an investigation into regimes of temperature, density, and activity not available from spatially detailed studies of our low-activity Sun. Our investigation makes use of simultaneous Chandra HETGS and HST/STIS high resolution spectra, along with non-contemporaneous FUSE and EUVE spectra, to probe the characteristics of the outer atmospheric plasma from the upper chromosphere to the corona. A detailed study of the coronal spectrum finds evidence of the inverse First Ionization Potential (FIP) effect, commonly seen in active stars. We examine the structures producing this emission through the shape of the emission measure distribution over a span of three decades in temperature, and the variation of electron density with electron temperature over a similar range. The correspondence of elements with ionic transitions in both X-ray and UV spectral ranges allows us to investigate the region in the atmosphere where the coronal abundance fractionation pattern begins.

RAO acknowledges funding through a Jansky fellowship from NRAO. RAO acknowledges funding through grants from SAO and STScI.

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

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