The Age, Formation and Evolution of the Elements in the Oldest Galactic Stars

Cowan，John“The Age，Formation，Evolution of the Elements in the Oldest Stars“AST-9986974本项目研究放射性元素的年龄、形成和演化，作为估算已知最古老恒星年龄的一种手段。 PI将利用最近在核反应和衰变率方面的改进来推导低金属丰度恒星中放射性元素的预期丰度，特别是钍、铀以及s和r过程元素。 为真实的恒星确定的丰度模式将与恒星演化后期的这些新的核合成计算进行比较。 这些结果很可能为我们的银河系和宇宙的年龄提供严格的限制。该项目的资金由美国国家科学基金会恒星天文天体物理学计划（AST/SAA）提供。

ABSTRACTCowan, John"The Age, Formation, & Evolution of the Elements in the Oldest Stars"AST-9986974This project investigates the age, formation and evolution of radioactive elements as a means of estimating the ages of the oldest stars known. The PI will use recent improvements in nuclear reaction and decay rates to derive expected abundances for radioactive elements in low-metallicity stars, particularly thorium, uranium and the s- and r-process elements. The abundance patterns determined for real stars will be compared with these new nucleosynthesis calculations for late stages of stellar evolution. The results are likely to provide hard limits on the ages for our Galaxy and the Universe.Funding for this project was provided by the NSF program for Stellar Astronomy & Astrophysics (AST/SAA).