Beryllium and boron abundance in the meteorites: A synthesis in interstellar grains

Journal Article · Wed Nov 01 04:00:00 EST 1978 · Astrophys. J., Lett. Ed.; (United States)

DOI:https://doi.org/10.1086/182814· OSTI ID:6589847

Dwek, E

We suggest that the high abundance of beryllium and boron found in the carbonaceous chondrites is due to the presence of irradiated interstellar graphite grains in those meteorites. The beryllium and boron are produced in the grains by an energetic proton irradiation that occurred at some stage in their lifetime. The identical /sup 11/B//sup 10/B ratio in the Earth and in the meteorites and the limited variations in the /sup 7/Li//sup 6/Li ratio between terrestrial and meteoritic samples indicate that these graphite grains were uniformly distributed over large portions of the preplanetary disk. The lower solar photospheric boron and beryllium abundance shows that no BeB--bearing graphite grains were mixed into the Sun, pointing to a distinct nuclear origin, quite possibly a synthesis in the interstellar medium by high-energy cosmic rays. The model therefore predicts a solar boron isotopic ratio of 2.3, compatible with that produced in the galactic cosmic-ray propagation model, but distinct from the terrestrial and meteoritic ratio of 4 that is produced in the grains. A measurement of this ratio in the solar photosphere will thus support or disprove our proposed model.

• Research Organization: W. K. Kellogg Radiation Laboratory, California Institute of Technology
• OSTI ID: 6589847
• Journal Information: Astrophys. J., Lett. Ed.; (United States), Journal Name: Astrophys. J., Lett. Ed.; (United States) Vol. 225:3; ISSN AJLEA
• Country of Publication: United States
• Language: English

Related Subjects

640101* -- Astrophysics & Cosmology-- Cosmic Radiation
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABUNDANCE
ALKALINE EARTH METALS
BERYLLIUM
BORON
CARBON
CHEMICAL COMPOSITION
CHONDRITES
ELEMENTS
GRAPHITE
INTERSTELLAR GRAINS
ISOTOPE RATIO
METALS
METEORITES
NONMETALS
NUCLEAR REACTIONS
PARTICLES
SEMIMETALS
SOLAR SYSTEM
STONE METEORITES