The Spectral Evolution of V382 Velorum (Nova Vela 1999)

Abstract

We present the spectral evolution of the shell of Nova Vel 1999 during the first 3 years after visual maximum. We monitored the ionization in the ejecta and verified an increase in ionization about 200 days after the outburst. In addition, an increase in the blue continuum was observed 565 days after the outburst, which is probably due to the reestablishment of the accretion disk in the system. The evolution of the forbidden lines' FWHM was followed and shows a significant velocity decrease during the period. The main results of our study suggest that the shell is highly heterogeneous and nonspherical. We also estimate shell electron temperatures and densities, as well as the central source temperature evolution. With these data we estimate lower limits for He, N, O, Ne, S, Ar, and Fe abundances, confirming this system as a neon nova. Both oxygen and neon abundance limits are relatively low when compared with other neon novae. However, the neon abundance in this nova is high when compared with the heavy-element abundances. We also found some indications that iron may be enhanced in the shell.