CNO abundances and the strengths of nova outbursts and hydrogen flashes on accreting white dwarfs
Simple theories of the accretion phase and expansion phase of hydrogen shell flashes on accreting white dwarfs are used to find the conditions under which classical novae occur. Particular attention is paid to the possibility that the CNO abundances in the accreted envelope are greatly enhanced relative to the Sun. It is shown that such an enhancement is necessary for fast novae, yet slow novae, such as DQ Her, can still occur with large CNO enhancements. An analysis of the observed properties of nova ejecta indicates that the white dwarfs in nova systems have masses in the range 1.02--1.18 M/sub sun/. It is found that in some novae, including RR Pic, CP Lac, and V603 Aql, the accretion rate deduced from the optical luminosity in quiescence is too high to allow accretion of sufficient envelope material to get the strong hydrogen flash needed for the nova outburst. Some possible resolutions of this problem are discussed. We also find it unlikely that recurrent novae are thermonuclear runaways on accreting white dwarfs.
- Research Organization:
- Department of Astronomy, University of Illinois at Urbana-Champaign
- OSTI ID:
- 5984447
- Journal Information:
- Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 267:2; ISSN ASJOA
- Country of Publication:
- United States
- Language:
- English
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Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABUNDANCE
CARBON
DWARF STARS
ELEMENTS
ERUPTIVE VARIABLE STARS
HYDROGEN BURNING
LUMINOSITY
MASS
MATHEMATICAL MODELS
NITROGEN
NONMETALS
NOVAE
NUCLEOSYNTHESIS
OPTICAL PROPERTIES
OXYGEN
PHYSICAL PROPERTIES
STAR ACCRETION
STAR BURNING
STAR EVOLUTION
STAR MODELS
STARS
VARIABLE STARS
WHITE DWARF STARS