A Focused Test of Whether Neutron-Capture Elements Are Another Expression of the Multiple Populations Phenomenon in Globular Clusters

球状星团是由数十万颗恒星组成的星团。 有超过100个球状星团围绕着我们的银河系。 在球状星团中的恒星中发现的原子元素保留了最早几代恒星的化学指纹。这些元素让我们得以一窥早期宇宙中大自然形成恒星和产生重元素（铁、铀等）的方式。就像今天在地球上发现的那样。该研究员将收集和解释在五个球状星团中发现的微量元素的新观测数据。 这些星系团在我们银河系形成之前就已经形成了。重元素之间的异常变化可能是球状星团多居群现象的另一种表现。这些变化是目前球状星团形成和演化的模型所无法预测的。使用麦哲伦望远镜的M2FS光谱仪收集的新光谱数据将解决这个问题。研究人员将根据较低质量的光谱数据进行观察，最终证实或反驳之前的想法。如果得到证实，该社区将获得一个新的工具来指导球状星团形成和演化的模型。如果遭到反驳，该社区可能会重新集中精力开发模型，充分解释银河系球状星团的化学和动力学特性。该项目还将导致开发一门新的入门课程，探索古老恒星中锻造的重元素与过去几代人塑造全球政治的核武器之间的联系。本课程将覆盖密歇根大学的广大本科生，包括许多不主修STEM学科的学生。该课程将向学生介绍科学在公共竞技场中的作用，特别是通过古代超新星的星尘如何成为核军备竞赛的关键成分的引人注目的故事来阐述。这将提高科学素养，加强公众对科学和技术的参与，并提高未来领导人的准备程度。

Globular clusters are groups of hundreds of thousands of stars. There are more than 100 globular clusters orbiting our Milky Way galaxy. The atomic elements found in stars in globular clusters retain the chemical fingerprints of the earliest generations of stars. These elements offer a glimpse into the ways that nature formed stars in the early Universe and produced the heavy elements (iron, uranium, etc.) like those found on Earth today. This investigator will collect and interpret new observational data on trace elements found in five globular clusters. These clusters were formed prior to the assembly of our galaxy. Abundance variations among the heavy elements may signal another expression of the multiple populations phenomenon in globular clusters. These variations are not predicted by current models of globular cluster formation and evolution. New optical spectroscopy data collected using the M2FS spectrograph at the Magellan Telescopes will settle the issue. The investigator will perform observations that will conclusively confirm or refute previous ideas based on lower-quality spectroscopic data. If confirmed, the community will gain a new tool to guide models of globular cluster formation and evolution. If refuted, the community may refocus its efforts to develop models that fully explain the chemical and dynamical properties of globular clusters in the Milky Way.This project will also result in the development of a new introductory course that explores the connections between heavy elements forged in ancient stars and the nuclear weapons that have shaped global politics over the last few generations. This course would reach a broad audience of undergraduates at the University of Michigan, including many students who are not majoring in one of the STEM disciplines. The course will introduce students to the role of science in the public arena, articulated specifically through the compelling story of how stardust from ancient supernovae became the key ingredient in the nuclear arms race. This will increase scientific literacy, enhance public engagement with science and technology, and improve the preparedness of future leaders.