Did Solar Energetic Particles Produce the Short‐lived Nuclides Present in the Early Solar System?

Abstract

Production of the short-lived nuclides 41Ca, 36Cl, 26Al, and 53Mn by solar energetic particles (SEP) interacting with dust grains of chondritic (\solar) composition is estimated considering a broad range of spectral parameters for the SEP and appropriate nuclear reaction cross sections. The dust grains are assumed to follow a power-law size distribution and to range in size from 10 km to 1 cm. The possibility that an enhanced Ñux of SEP from an active early (T Tauri) Sun could have been responsible for the production of these short-lived nuclides in the early solar system is investigated. SEP production of 41Ca and 36Cl will match their abundances in the early solar system inferred from meteorite data if the SEP irradiation duration was D 5 ] 105È106 yr and the SEP Ñux was higher by a factor of more than 5 ] 103 than the contemporary long-term averaged value of (E [ 10 MeV) D 100 cm~2 s~1.