AAS 203rd Meeting, January 2004
Session 84 Binary Stars
Poster, Wednesday, January 7, 2004, 9:20am-6:30pm, Grand Hall

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[84.09] FUSE Observations of Molecular Hydrogen Emission from Mira B

B.E. Wood (JILA/U. Colorado), M. Karovska (SAO)

The Far Ultraviolet Spectroscopic Explorer (FUSE) observed the UV spectrum of Mira A's wind-accreting companion star, Mira B, on 2001 November 27. The FUSE spectrum is similar to an older UV spectrum of Mira B from 1999 taken by the Hubble Space Telescope (HST) in that it is dominated by narrow H2 lines fluoresced by H I Lyman-\alpha. The FUSE H2 lines are mostly Werner band lines, many of them never before identified in an astrophysical spectrum. The emission may be coming from H2 within Mira A's wind, which is being fluoresced, heated, and dissociated as it approaches the companion. Combining the FUSE and HST data, we find that the emission can be reproduced by an H2 layer surrounding Mira B with a temperature and column density of T=3900 K and log N(H2)=17.1, respectively. The HST and FUSE data both have suprisingly weak continuum and high-temperature emission line fluxes compared to older data from the International Ultraviolet Explorer (IUE), suggesting that the accretion rate onto Mira B has fallen dramatically in recent years. This work is supported by NASA grant NAG5-11950 to the University of Colorado.

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

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Bulletin of the American Astronomical Society, 35#5
© 2003. The American Astronomical Soceity.