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Session 79 - CVs and Novae.
Display session, Wednesday, January 17
North Banquet Hall, Convention Center

[79.09] A Photospheric Analysis of the Underlying White Dwarf in the High Accretion Rate Dwarf Nova RX Andromedae

Q. Nguyen, K. Belle, D. Fabian, M. Huang, E. M. Sion (Villanova U.)

It has been shown that a number of dwarf novae both above and below the period gap reveal their underlying white dwarf accreters during dwarf nova quiescence. The dwarf nova RX And is one of only a handful of systems above the period gap (where mass transfer rates are generally higher and cataclysmic binary system ages may be younger ) which show clear spectroscopic evidence of the white dwarf. We present an analysis of the IUE spectra of RX AND during optical quiescence when the white dwarf dominates the far ultraviolet light of the system. We have calculated a grid of solar composition, high gravity model atmospheres with TLUSTY and SYNSPEC (Hubeny 1988, 1995) to determine the effective temperature, surface gravity, approximate chemical abundances of its accreted atmosphere and constraints on the rotational velocity Vsini of the underlying white dwarf. The results of detailed synthetic spectral fitting of the IUE SWP low resolution spectra will be presented and fundamental parameters of the white dwarf photosphere, its lower limit cooling age and implications for the accretion physics, will be summarized.

This work has been supported by NASA LTSA grant NAGW-3726 and by a summer research grant from the NASA Delaware Space Grant Colleges Consortium.

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