POSTER PAPER 9.05
Detection of H2 Emission from Mira B with the HST
Brian E. Wood, Margarita Karovska, Warren Hack
Institute: JILA, University of Colorado
Institute: Smithsonian Astrophysical Observatory
Institute: Space Telescope Science Institute
Contact Email:
Abstract:
We present results from our HST/STIS observations of Mira's companion
(Mira B) carried out in 1999 August. Mira B is a compact object
surrounded by an accretion disk at a distance of at least 70 AU from Mira.
The high resolution ultraviolet spectra of Mira B obtained using STIS show
that the spectral signatures of the accretion disk have changed dramatically
when compared to HST observations obtained only four years earlier. The STIS
UV spectrum detects numerous, narrow H2 lines fluoresced by H I
Lya which have never been seen previously in spectra of the Mira AB
system. Furthermore, the continuum fluxes in the Mira B spectra are much
lower than observed before, at least an order of magnitude when compared to
the 1995 HST/FOC objective prism spectra, and lower than ever observed by
IUE. These significant changes in the spectral distribution of Mira B might
be due to disk instabilities or inhomogeneity in Mira A's massive wind, or
a combination of the two.
Index Keywords: Mira B; Ultraviolet; Molecular Hydrogen; Fluorescence; Accretion Disk
Previous: Luttermoser
Next: De Laverny
Up: Poster Index
Up: Top Index
Manuscript submitted: 2001-Sep-06
"The Future of Cool-Star Astrophysics", 2003, Eds. A. Brown,
G. M. Harper, & T. R. Ayres.
Proceedings of 12th Cambridge Workshop on Cool Stars, Stellar Systems,
& The Sun,
© 2003 University of Colorado.