On the Hayashi Effect in the Early Phases of Gravitational Contraction of the Sun
Computations are made using a program for the subphotospheric layers, including opacity effects due to the negative hydrogen ion and to Rayleigh scattering. Under thermodynamic conditions completely convective models are found to occur, displaced toward late types in the H-R (Hertzsprang-Russell) diagram. The models investigated range from the late K subclasses to about M/sub 3/. Nonthermodynamic effects are considered. It appears that free electrons produced by high-energy particles are capable of modifying the results by reducing the effective temperature and luminosity, but not by completely removing the convective structure. Nor does it seem likely that opacity effects arising from solid particles can destroy the convective structure. The possibility remains, however, that convective efficiency in the subphotospheric layers could be much reduced by a magnetic field at the stage where the planetary material separated from the Sun, and during the condensation of the first planetesimals and of the parent bodies of the meteorites. Only by a suppression of the highluminosity convective models during this phase does it seem possible to explain the presence of water in meteorites, and the likely presence of any icy matrix in the first planetesimals. (auth)
- Research Organization:
- Univ. of Cambridge (United Kingdom)
- Sponsoring Organization:
- USDOE
- NSA Number:
- NSA-17-036555
- OSTI ID:
- 4638588
- Journal Information:
- Monthly Notices of the Royal Astronomical Society, Vol. 126, Issue 1; Other Information: Orig. Receipt Date: 31-DEC-63; ISSN 0035-8711
- Publisher:
- Royal Astronomical Society
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
Similar Records
GLOBAL MODELING OF NEBULAE WITH PARTICLE GROWTH, DRIFT, AND EVAPORATION FRONTS. I. METHODOLOGY AND TYPICAL RESULTS
DEUTERONOMY. SYNTHESIS OF DEUTERONS AND THE LIGHT NUCLEI DURING THE EARLY HISTORY OF THE SOLAR SYSTEM