منابع مشابه
The role of NCO reaction chain on the He ignition in degenerate stellar structures
Some 25 years ago [5] it has been suggested that the 14 N (e − , γ) 14 C(α, γ) 18 O reaction (NCO reaction chain) plays a pivotal role in the onset of the Helium flash in the core of a low mass Red Giant Branch (RGB) star (see [3] and [4]). In fact in the He core the Fermi energy is large enough to approach the energy for the e-capture on 14 N well before the 3α reactions produce energy at a si...
متن کاملDiffusion and the occurrence of hydrogen shell flashes in helium white dwarf stars
In this paper we investigate the effects of element diffusion on the structure and evolution of low-mass helium white dwarfs. Attention is focused mainly on the occurrence of hydrogen shell flashes induced by diffusion processes during cooling phases. Physically sound initial models with stellar masses of 0.406, 0.360, 0.327, 0.292, 0.242, 0.196, 0.169 and 0.161 M⊙ are constructed by applying m...
متن کاملClassical helium atom with radiation reaction.
We study a classical model of helium atom in which, in addition to the Coulomb forces, the radiation reaction forces are taken into account. This modification brings in the model a new qualitative feature of a global character. Indeed, as pointed out by Dirac, in any model of classical electrodynamics of point particles involving radiation reaction one has to eliminate, from the a priori concei...
متن کاملA NEW ESTIMATION OF MASS ACCUMULATION EFFICIENCY IN HELIUM SHELL FLASHES TOWARD TYPE Ia SUPERNOVA EXPLOSIONS
We have calculated the mass accumulation efficiency during helium shell flashes to examine whether or not a carbon-oxygen white dwarf (C+O WD) grows up to the Chandrasekhar mass limit to ignite a Type Ia supernova (SN Ia) explosion. It has been frequently argued that luminous super-soft X-ray sources (SSSs) and symbiotic stars are progenitors of SNe Ia. In such systems, a C+O WD accretes hydrog...
متن کاملMass accumulation efficiency in helium shell flashes for various white dwarf masses
We have calculated the mass accumulation efficiency during helium shell flashes on white dwarfs (WDs) of mass 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, and 1.35 M⊙ for the helium accretion rates log ṀHe (M⊙ yr ) = −7.4 to −5.8. This efficiency is a crucial factor for binary evolutions of Type Ia supernovae. For less massive WDs (< 0.8 M⊙) no wind mass loss occurs and all the accreted mass accumulates ...
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ژورنال
عنوان ژورنال: International Astronomical Union Colloquium
سال: 1988
ISSN: 0252-9211
DOI: 10.1017/s0252921100093453