Rubidium-Rich Asymptotic Giant Branch Stars
Rubidium-Rich Asymptotic Giant Branch Stars
复制标题
富铷渐近巨星分支星
DOI：
10.1126/science.1133706
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发表时间：
2006
期刊：
影响因子：
56.9
通讯作者：
J. Trigo‐Rodríguez
中科院分区：
文献类型：
--
作者：
D. A. García;P. Garcı́a;B. Plez;F. D’Antona;A. Manchado;J. Trigo‐Rodríguez
在渐近巨支星（AGB）中富中子元素的核合成中，中子源的识别是一个长期争论的问题。我们报告了银河系中中等质量（4到8个太阳质量）的AGB恒星，它们富含铷，这是由于长寿命放射性同位素87Rb的过量生产造成的，正如40年前理论上预测的那样。这一发现提供了直接的观测证据，表明22Ne(α,n)25Mg反应一定是这些恒星中主要的中子源。这些恒星挑战了我们对中质量恒星演化后期的理解，并可能在早期太阳星云中促进了高度可变的Rb/Sr环境。
A long-debated issue concerning the nucleosynthesis of neutron-rich elements in asymptotic giant branch (AGB) stars is the identification of the neutron source. We report intermediate-mass (4 to 8 solar masses) AGB stars in our Galaxy that are rubidium-rich as a result of overproduction of the long-lived radioactive isotope 87Rb, as predicted theoretically 40 years ago. This finding represents direct observational evidence that the 22Ne(α,n)25Mg reaction must be the dominant neutron source in these stars. These stars challenge our understanding of the late stages of the evolution of intermediate-mass stars and would have promoted a highly variable Rb/Sr environment in the early solar nebula.