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Session 6 - Novae and Supernovae.
Display session, Monday, June 08
Atlas Ballroom,
The nova outburst is a consequence of the accretion of hydrogen rich material onto a white dwarf in a close binary system and both theory and observations show that the accreting material mixes with core material during the outburst. Abundance determinations of nova ejecta shows that the core material is either carbon and oxygen or oxygen, neon, and magnesium. We have determined the ejecta abundances for V838 Her (1991), OS And (1986), V693 CrA (1981), PW Vul (1984), LMC 1988 #1, and LMC 1990 #1 using both optical and ultraviolet data. Our analysis technique uses CLOUDY (Ferland 1996) in combination with an optimization method obtained from high energy physics (MINUIT: James and Roos 1993). Our predicted line fluxes are in excellent agreement with the observations. We are also analyzing spectra obtained early in the outburst, when the expanding shell is optically thick, with stellar atmospheres computed with PHOENIX (Hauschildt et al. 1997, ApJ, 490,803). We will present the results of our studies using both these methods. Our re-analyses of V693 CrA and PW Vul resolved the problems with the previous studies.
The author(s) of this abstract have provided an email address for comments about the abstract: sumner.starrfield@asu.edu