Evidence for a Single Stellar Environment of R-Process Nucelosynthesis from Live ^(247)Cm in the Early Solar System

Abstract

The Early Solar System (ESS) abundance of short-lived radionuclides (SLR) can be interpreted in terms of a free-decay interval (Δ) or a mixing timescale (τ), which correspond to complete or partial isolation from fresh nucleosynthetic inputs of the molecular could core parental to the solar system. For r-nuclides, however, the abundances measured in ESS materials require less isolation for ^(107)Pd and ^(182)Hf (Δ~ 5 Myr) than for ^(129)I (Δ=100±7 Myr) and ^(244)Pu (Δ=158±85 Myr) [1]. To make sense of these observations, models have proposed the existence of up to three different r-processes producing, respectively, the light r-nuclides, the heavy r-nuclides and the actinides [1-4]. In this work [5], we determined the ESS abundance of another short-lived r-nuclide, the long sought after ^(247)Cm [e.g., 6-7], and show how this additional constraint is consistent with either three different r-processes, or, and more likely, a single stellar environment of r-process nucleosynthesis and a partial s-process origin for ^(107)Pd and ^(182)Hf.