美国芝加哥大学Justin Y. Hu团队研究了原行星盘中稀土元素核合成异常与尘埃输运。这一研究成果发表在2025年7月11日出版的《科学-进展》杂志上。

太阳系天体的大小、密度和化学特征都是由原行星盘阶段的物质传输所决定的。这包括携带核合成异常的难熔稀土颗粒从内太阳系向外太阳系的运输。

研究组发现，细粒富钙铝夹杂物（CAIs）中的稀土元素（REE）同位素表现出异常，这是由于r-、s-和p-过程核合成的不完全混合造成的。数据点定义了两种相关性，最好的解释是三个同位素储层在两个连续阶段的混合，其中一个阶段涉及p过程组分的可变混合。研究组认为CAI前体形成于太阳系内部，随后被猎户座FU的爆发从盘面运送到包络层，在那里它们与同位素不同的储层混合，然后沉淀在中间面。

附：英文原文

Title: Rare earth element nucleosynthetic anomalies and dust transport in the protoplanetary disk

Author: Justin Y. Hu, Franois L. H. Tissot, Ren T. C. Marquez, Oliver Shorttle, Cathie J. Clarke, Andrew D. Sellek, Nicolas Dauphas, Bruce L. A. Charlier, Ingo Leya, Reika Yokochi, Thomas J. Ireland, Helen M. Williams

Issue&Volume: 2025-07-11

Abstract: The size, density, and chemical characteristics of solar system bodies have been shaped by material transport during the protoplanetary disk stage. This includes transport from the inner to outer solar system of refractory dust grains that carry nucleosynthetic anomalies. Here, we show that rare earth element (REE) isotopes in fine-grained calcium-aluminum–rich inclusions (CAIs) display anomalies stemming from incomplete mixing of r-, s-, and p-process nucleosynthesis. The data points define two correlations, which are best explained by mixing between three isotopic reservoirs in two successive stages, one of which involved a variable admixture of a p-process component. We propose that CAI precursors formed in the inner solar system and were subsequently transported by FU Orionis outbursts from the disk to the envelope where they mixed with an isotopically distinct reservoir before settling on the midplane.

DOI: adv3148

Source: https://www.science.org/doi/10.1126/sciadv.adv3148