Abstract
view Abstract Citations (70) References (41) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Helium abundance anomalies and radiative forces in stellar envelopes. Michaud, G. ; Montmerle, T. ; Cox, A. N. ; Magee, N. H., Jr. ; Hodson, S. W. ; Martel, A. Abstract To determine at what effective temperature the largest amount of helium can be supported, detailed radiative acceleration calculations are made for helium in stellar envelopes with log g between 3.5 and 4.5 and effective temperatures between 10,000 and 25,000 K. It is found that as the effective temperature increases above 18,000 K, the radiative acceleration does not increase substantially in the envelope; thus, diffusion cannot lead to (He-4)-rich stellar envelopes. A calculation is made of the contribution of the lines of He I to the effective radiative acceleration, showing strong dependence on the collisional excitation and ionization rates of the excited states of He I, after absorption of a photon. Publication: The Astrophysical Journal Pub Date: November 1979 DOI: 10.1086/157489 Bibcode: 1979ApJ...234..206M Keywords: Abundance; Helium; Radiative Transfer; Stellar Atmospheres; Stellar Envelopes; Gas Ionization; Line Spectra; Particle Acceleration; Photoionization; Stellar Temperature; Stellar Winds; Astrophysics; Helium:Stellar Atmospheres; Radiative Transfer:Stellar Atmospheres; Stellar Atmospheres:Models full text sources ADS |
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