Fossil records of early solar irradiation and cosmolocation of the CAI factory: A reappraisal

Bekaert, David V.; Auro, Maureen; Shollenberger, Quinn R.; Liu, Ming-Chang; Marschall, Horst; Burton, Kevin W.; Jacobsen, Benjamin; Brennecka, Gregory A.; McPherson, Glenn J.; von Mutius, Richard; Sarafian, Adam; Nielsen, Sune G.

Abstract

Calcium-aluminum–rich inclusions (CAIs) in meteorites carry crucial information about the environmental conditions of the nascent Solar System prior to planet formation. Based on models of 50V–10Be co-production by in-situ irradiation, CAIs are considered to have formed within ~0.1 AU from the proto-Sun. Here, we present vanadium (V) and strontium (Sr) isotopic co-variations in fine- and coarse-grained CAIs and demonstrate that kinetic isotope effects during partial condensation and evaporation best explain V isotope anomalies previously attributed to solar particle irradiation. We also report initial excesses of 10Be and argue that CV CAIs possess essentially a homogeneous level of 10Be, inherited during their formation. Based on numerical modeling of 50V–10Be co-production by irradiation, we show that CAI formation during protoplanetary disk build-up likely occurred at greater heliocentric distances than previously considered, up to planet-forming regions (~1AU), where solar particle fluxes were sufficiently low to avoid substantial in-situ irradiation of CAIs.

Citation

Bekaert, D. V., Auro, M., Shollenberger, Q. R., Liu, M.-C., Marschall, H., Burton, K. W., Jacobsen, B., Brennecka, G. A., McPherson, G. J., von Mutius, R., Sarafian, A., & Nielsen, S. G. (2021). Fossil records of early solar irradiation and cosmolocation of the CAI factory: A reappraisal. Science Advances, 7(40), Article eabg8329. https://doi.org/10.1126/sciadv.abg8329

• Journal Article Type: Article
• Online Publication Date: Sep 29, 2021
• Publication Date: 2021
• Deposit Date: Oct 4, 2021
• Publicly Available Date: Oct 4, 2021
• Journal: Science Advances
• Publisher: American Association for the Advancement of Science
• Peer Reviewed: Peer Reviewed
• Volume: 7
• Issue: 40
• Article Number: eabg8329
• DOI: https://doi.org/10.1126/sciadv.abg8329
• Public URL: https://durham-repository.worktribe.com/output/1237826