Diffusion-induced hydrogen burning and the evolution of DA white dwarfs

Abstract

view Abstract Citations (31) References (25) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Diffusion-induced hydrogen burning and the evolution of DA white dwarfs. Michaud, G. ; Fontaine, G. Abstract The evolution of the hydrogen distribution of a 0.6 solar mass DA white dwarf in the presence of diffusion and nuclear burning is followed. An approximate solution is obtained by decoupling the diffusion calculations from the computations of the model structure. A DA white dwarf starting its life with a hydrogen layer containing q(H) of about 0.0001-0.0004 reaches an effective temperature of 10,000 K with only q(H) of about 3 x 10 to the -7th left over. Diffusion-induced hydrogen burning thus explains the apparent conflict between standard evolution theory and the results of recent pulsational studies of white dwarfs. The process also implies that hydrogen burning is a nonnegligible energy source in the evolution of an isolated white dwarf, contrary to common belief. Finally, turbulence is shown to be extremely small in hydrogen-rich white dwarfs. Turbulence is ruled out as the cause of heavy elements appearing in some white dwarf spectra. The implications of these results are briefly discussed. Publication: The Astrophysical Journal Pub Date: August 1984 DOI: 10.1086/162364 Bibcode: 1984ApJ...283..787M Keywords: Stellar Evolution; Thermonuclear Reactions; White Dwarf Stars; Diffusion; Mass Distribution; Stellar Cores; Stellar Models; Turbulence; Astrophysics full text sources ADS | data products SIMBAD (1)