该课题组研究人员测量了32块陨石中的钾同位素比率，并确定了同位素钾-40的核合成异常。碳质球粒陨石(CC)中的异常比非碳质球粒陨石(NC)的异常更大、更多变，表明碳质球粒陨石继承了更多超新星核合成产生的物质。地球的钾-40异常与非碳质球粒陨石的异常接近，说明地球钾主要由非碳质球粒陨石输送。
据介绍，陨石以核合成异常的形式记录了发生在太阳系形成之前和期间的过程:与太阳系模式不同的同位素组成。在大块陨石尺度上，钾等挥发性元素很少出现核合成异常。
附：英文原文
Title: Meteorites have inherited nucleosynthetic anomalies of potassium-40 produced in supernovae
Author: Nicole X. Nie, Da Wang, Zachary A. Torrano, Richard W. Carlson, Conel M. O’D. Alexander, Anat Shahar
Issue&Volume: 2023-01-27
Abstract: Meteorites record processes that occurred before and during the formation of the Solar System in the form of nucleosynthetic anomalies: isotopic compositions that differ from the Solar System patterns. Nucleosynthetic anomalies are rarely seen in volatile elements such as potassium at bulk meteorite scale. We measured potassium isotope ratios in 32 meteorites and identified nucleosynthetic anomalies in the isotope potassium-40. The anomalies are larger and more variable in carbonaceous chondrite (CC) meteorites than in noncarbonaceous (NC) meteorites, indicating that CCs inherited more material produced in supernova nucleosynthesis. The potassium-40 anomaly of Earth is close to that of the NCs, implying that Earth’s potassium was mostly delivered by NCs.
DOI: abn1783
Source: https://www.science.org/doi/10.1126/science.abn1783