The Early Ultraviolet Evolution of the ONeMg Nova V382 Velorum 1999
Gehrz, Robert D.; Bond, Howard E.; Krautter, Joachim; Woodward, Charles E.; Evans, A.; Shore, Steven N.; Hauschildt, Peter H.; Starrfield, Sumner; Downes, Ronald A.; Schwarz, Greg
Italy, United States, United Kingdom, Germany
Abstract
We present a multiwavelength study of the ONeMg Galactic nova V382 Velorum 1999 using HST/STIS and FUSE ultraviolet spectra and comparisons with published ground-based optical spectra. We find a close match to the basic phenomenology of another well-studied ONeMg nova, V1974 Cygni (Nova Cyg 1992), in particular, to the spectral development through the start of the nebular phase. Following an ``iron curtain'' phase, the nova proceeded through a stage of P Cygni line profiles on all important resonance lines, as in many ONeMg novae and unlike the CO class. Emergent emission lines displayed considerable structure, as seen in V1974 Cyg, indicating fragmentation of the ejecta at the earliest stages of the outburst. Analysis and modeling of our ultraviolet spectra suggest that (4-5)×10-4Msolar of material was ejected and that the distance to the nova is ~=2.5 kpc. Relative to solar values, we find the following abundances: He=1.0, C=0.6+/-0.3, N=17+/-4, O=3.4+/-0.3, Ne=17+/-3, Mg=2.6+/-0.1, Al=21+/-2, and Si=0.5+/-0.3. Finally, we briefly draw comparisons with Nova LMC 2000, another ONeMg nova, for which similar data were obtained with HST and FUSE.
Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract 5-26555. These observations are associated with proposals for programs GO 8540 and GO 8671. Also based on observations made with the NASA-CNES-CSA Far Ultraviolet Spectroscopic Explorer. FUSE is operated for NASA by the Johns Hopkins University under NASA contract NAS 5-32985.