Certain nuclear isomers are well known to affect nucleosynthesis with important observable consequences (e.g., ²⁶Al and ¹⁸⁰Ta). We study the impact of nuclear isomers in the context of rapid neutron capture process (r-process) nucleosynthesis. We demonstrate that nuclear isomers are dynamically populated in the r process and that some are populated far from thermal equilibrium; this makes them astrophysical isomers, or “astromers.” We compute thermally mediated transition rates between long-lived isomers and the corresponding ground states in neutron-rich nuclei. We calculate the temperature-dependent β-decay feeding factors, which represent the fraction of material going to each of the isomer and ground state daughter species from the β-decay parent species. We simulate nucleosynthesis following the decay of a solar-like r-process composition and include as separate species nuclear excited states with measured terrestrial half-lives greater than 100 μs. We introduce a new metric to identify those astromers most likely to be influential and summarize them in a table. Notable entries include many second peak nuclei (e.g., the Te isotopic chain) and previously overlooked isomers in stable nuclei (e.g., ¹¹⁹Sn, ¹³¹Xe, and ¹⁹⁵Pt). Finally, we comment on the capacity of isomer production to alter radioactive heating in an r-process environment.

众所周知，某些核异构体会影响核合成并产生重要的可观察结果（例如，²⁶ Al 和¹⁸⁰ Ta）。我们研究了核异构体在快速中子俘获过程 ( r- process ) 核合成背景下的影响。我们证明核异构体在r过程中动态填充，并且一些远离热平衡；这使他们成为天体物理异构体，或“天文学家”。我们计算了长寿命异构体与富中子核中相应基态之间的热介导跃迁率。我们计算温度相关的β-衰变供给因子，代表从β-衰变亲本物种进入每个异构体和基态子代物种的物质比例。我们在类似太阳的r 过程组合物衰变后模拟核合成，并包括作为独立物种的核激发态，其测量的地球半衰期大于 100 μ s。我们引入了一个新指标来识别那些最有可能有影响力的天体并将它们汇总在一个表格中。值得注意的条目包括许多第二峰核（例如 Te 同位素链）和先前被忽视的稳定核中的异构体（例如¹¹⁹ Sn、¹³¹ Xe 和¹⁹⁵铂）。最后，我们评论了异构体生产在r 过程环境中改变放射性加热的能力。