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C. S. Pilman, E. M. Sion (Villanova Un.), P. Szkody (Un. of Washington), B. Gansicke (Un. of Gottingen)
We report on HST STIS observations of the May 2000 superoutburst of the dwarf nova VW Hydri. We have carried out a synthetic spectral analysis of this system using model accretion disk and high-gravity model photospheres. The spectra cover the beginning, middle, and end of the superoutburst. All of the spectra are dominated by strong absorption lines due to CIII (1175Å), Lyman \alpha (1216Å), NIV (1238, 1242Å), SII (1260-65Å), SIII (1300Å), CII (1335Å), SIV (1394, 1402Å) and CIV (1548, 1550Å). We discuss the evolution of the far UV energy distribution and line structure during the superoutburst. We present the results of multicomponent fitting involving a heated white dwarf plus an accretion disk. We confirm the absence of any P Cygni line structure in the STIS spectra. A comparsion of our derived parameters for VW Hydri in superoutburst are compared with the results of other multiwavelength spectroscopic observations.
Acknowledgements: This work was supported by NASA grant GO8139 and by NSF grant AST 99-01955 to Villanova University.