Vanadium isotope constraints on the cosmolocation of the CAI factory

摘要: Calcium-Aluminum-rich inclusions (CAIs) in meteorites are the oldest dated solids that formed within the Solar System. As such, they carry crucial information regarding the structure and conditions of the protoplanetary disk (PPD), before any of the planets formed1. CAI formation is widely thought to have occurred within~ 0.1 AU from the proto-Sun, based on (i) the presence of high temperature minerals rich in refractory elements (Ca, Al, Ti) 2, and (ii) quantitative constraints from the co-production of 50V and 10Be through in-situ irradiation of CAIs3. However, because vanadium (V) only has two stable isotopes (50V and 51V), any unresolved contribution from nucleosynthetic and mass-dependent stable isotope fractionation effects could introduce a bias in our interpretation of V isotope variations in CAIs. Here, we present V and strontium (Sr) isotopic co-variations in fine-and coarse-grained CAIs from the Allende …