CNO abundances and hydrodynamic studies of the Nova outburst. V. 1.00 M/sub sun/ models with small mass envelopes

We report on an investigation into the consequences of thermonuclear runaways in 10-4 M/sub sun/ accreted hydrogen envelopes on 1.00 M/sub sun/ white dwarfs. These evolutionary sequences predict that from 10-5 M/sub sun/ to 5 x 10-5 M/sub sun/ will be ejected with speeds from 300 to 3800 km s-1 (kinetic energies of 1044-1045 ergs). Absolute visual magnitudes as high as -8.1 mag are attained, well within the observed range for fast novae. In addition, the shapes of the theoretical light curves are more reminiscent of an observed fast nova light curve than those in our earlier studies.The ejected material is stongly enhanced in the products of incomplete CNO burning: the most abundant of the ejected nuclei is 13C, followed by 14N and 12C. The differences from previous studies are attributable to the lower peak temperatures reached in these sequences. These models also produce a large (approx.200) overabundance of 7Li, suggesting that novae may represent significant contributors to the galactic enrichment of this nucleus.We discuss the effects of circumbinary material on the light curve. We suggest that the presence of this gas, the remnant of nonconservative mass transfer, can strongly affect the shape of the light curve around maximum visual magnitude in an actual nova outburst.We find, as in our earlier work, that these models do not eject their entire accreted envelopes in the earliest stages of the outburst. The residual envelopes quickly evolve to configurations which are hot and bright, representing the probable source for the UV radiation observed in all recent classical novae