Open AccessObservational and theoretical studies of the nova outburst
Author(s) -
S. Starrfield,
K. M. Vanlandingham,
Guenter Schwarz
Publication year - 1998
Language(s) - English
Resource type - Reports
DOI - 10.2172/588554
Subject(s) - white dwarf , physics , neon , astrophysics , black dwarf , oxygen , carbon fibers , accretion (finance) , hydrogen , nova (rocket) , atomic physics , stars , materials science , aeronautics , engineering , quantum mechanics , argon , composite number , composite material
A nova outburst is one consequence of the accretion of hydrogen rich material onto a white dwarf in a close binary system. The strong electron degeneracy of a massive white dwarf drives the temperatures in the nuclear burning region to values exceeding 108K under all circumstances. As a result, a major fraction of the CNO nuclei in the envelope are transformed into e{sup +}-decay nuclei, which constrains the nuclear energy generation and yields non-solar CNO isotopic abundance ratios. In addition, the observations demonstrate that white dwarf core material is dredged up into the accreted layers and these nuclei are the catalysts for producing peak rates of energy generation that can exceed 10{sup 16} erg gm{sup -1}s{sup -1}. Observations show that there are two compositional classes of novae, one that occurs on a carbon-oxygen white dwarf and the other that occurs on an oxygen-neon-magnesium white dwarf