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Paper: The nature of classical nova explosions
Volume: 261, The Physics of Cataclysmic Variables and Related Objects
Page: 576
Authors: Truran, J. W.
Abstract: The outbursts of classical novae are understood to be a consequence of thermonuclear runaways occurring in accreted hydrogen shells on the surfaces of white dwarfs in close binary systems. The carbon-nitrogen-oxygen (CNO) cycle hydrogen burning sequences which dictate the energetics also act to constrain the energy release on a dynamic timescale. Envelope enrichments in the abundance levels of carbon, oxygen, and neon, such as are observed to be a characteristic feature of nova ejecta, are thus required to power the fastest novae. The mechanism by which the dredge-up of CO and ONe matter from the underlying white dwarf gives rise to these enrichments remains the most critical unresolved issue in nova research. Convective mixing associated with the earliest stages of the thermonuclear runaway, at temperatures of order 20-30 times 106K, has seemed the most promising explanation. Multidimensional hydrodynamic simulations of this problem to date have, however, given conflicting results. The current status of studies of the enrichment mechanism and its implications for nucleosynthesis in novae, the light curves of fast novae, and the masses of nova nebular ejecta will be reviewed.
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