Early Solar System irradiation quantified by linked vanadium and beryllium isotope variations in meteorites

Abstract

X-ray emission in young stellar objects (YSOs) is orders of magnitude more intense than in main sequence stars1,2, suggestive of cosmic ray irradiation of surrounding accretion disks. Protoplanetary disk irradiation has been detected around YSOs by HERSCHEL3. In our solar system, short-lived 10Be (half-life = 1.39 My4), which cannot be produced by stellar nucleosynthesis, was discovered in the oldest solar system solids, the calcium-aluminium-rich inclusions (CAIs)5. The high 10Be abundance, as well as detection of other irradiation tracers6,7, suggest 10Be likely originates from cosmic ray irradiation caused by solar flares8. Nevertheless, the nature of these flares (gradual or impulsive), the target (gas or dust), and the duration and location of irradiation remain unknown. Here we use the vanadium isotopic composition, together with initial 10Be abundance to quantify irradiation conditions in the early Solar System9. For the initial 10Be abundances recorded in CAIs, 50V excesses of a few per mil relative to chondrites have been predicted10,11. We report 50V excesses in CAIs up to 4.4 per mil that co-vary with 10Be abundance. Their co-variation dictates that excess 50V and 10Be were synthesised through irradiation of refractory dust. Modelling of the production rate of 50V and 10Be demonstrates that the dust was exposed to solar cosmic rays produced by gradual flares for less than 300 years at about 0.1 au from the protoSun.

References in corpus (2)

• X-ray emitting young stars in the Orion Nebula
• Stellar Activity on the Young Suns of Orion: COUP Observations of K5-7 Pre-Main Sequence Stars

Cited by in corpus (11)

• Fingerprints of the protosolar cloud collapse in the Solar System II: Nucleosynthetic anomalies in meteorites
• On the Origin of the Early Solar System Radioactivities. Problems with the AGB and Massive Star Scenarios
• Formation and evolution of a protoplanetary disk: combining observations, simulations and cosmochemical constraints
• The JCMT Transient Survey: An Extraordinary Submillimetre Flare in the T Tauri Binary System JW 566
• On beryllium-10 production in gaseous protoplanetary disks and implications on the astrophysical setting of refractory inclusions
• Evidence for magnetic activity at starbirth: a powerful X-ray flare from the Class 0 protostar HOPS 383
• The JCMT Transient Survey: Single Epoch Transients and Variability of Faint Sources
• Nebular history of an ultrarefractory phase bearing CAI from a reduced type CV chondrite
• Quantifying the high early solar cosmic ray flux with cosmogenic neon isotopes in refractory minerals
• Self-consistent Conditions for ${}^{26}$Al Injection into Protosolar Disk from a Nearby Supernova
• Radioactive Planet Formation