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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[55.04] M Dwarf Metallicities: Towards a Technique

J. L. Bean, C. Sneden, G. F. Benedict (University of Texas and McDonald Observatory), C. M. Johns-Krull (Rice University)

In our galaxy, M dwarfs are the most abundant stellar objects. They make up over 70% of stars in number and contribute over 40% of the total stellar mass content (Henry et al. 1998). Despite these overwhelming numbers, M dwarfs remain one of the least understood stellar types due to a lack of empirical data concerning their basic parameters, particularly metallicities. Here we present results from an analysis of visual binary star compositions. This analysis shows that the only technique that has been used successfully to determine the metallicity of an M dwarf, the technique of Valenti et al. (1998), is inconsistent with a differential analysis of warmer stars. We discuss possible reasons for these inconsistencies and report our progress to improve the technique. The motivation for this work comes from the importance of metallicity in answering two questions: How does varying metallicity affect the luminosity of M dwarfs; and, is there any correlation between the frequency of the presence of planetary mass compansions around M dwarfs and the host star's metallicity?

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

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