NOVA-V351-PUPPIS-1991 - A MULTIWAVELENGTH STUDY OF THE NEBULAR PHASE

We combine ground-based optical and IUE spectrophotometry to study the physical conditions in the shell of Nova V351 Puppis 1991. The struct ure and the evolution of the shell during the early nebular (i.e. opti cally thin) phase are discussed in this paper. The reddening, derived from recombination lines, is E(B - V) = 0.72 +/- 0.10. The optical/UV light curves imply a distance of 3.0 +/- 0.5 kpc. These values are fou nd to be consistent with a study of the reddening in the stellar field near the nova. Abundances from the emission-line spectra yield enhanc ements within the predictions of thermonuclear runaway models for clas sical novae, Relative to solar by number, they are: He/H = 1.7, C/H = 3.5, N/H = 130, O/H = 38, Ne/H = 120, Al/Si = 28. The shell shows a lo w ejected mass (M(ej) similar to 10(-7) M(.)), implying a high-mass wh ite dwarf. The optical spectra reveal a strong red excess, which we te ntatively attribute to the red companion. The strength of this continu um suggests that the companion is either a giant or an irradiated main -sequence star.