Collaborative Research: The Weirdest Stars in the Universe: Illuminating the Origins and Evolution of Thorne-Zytkow Objects

合作研究：宇宙中最奇怪的恒星：阐明索恩-齐特科天体的起源和演化

• 批准号: 2305225
• 负责人: Philip Massey
• 金额: $ 16.87万
• 依托单位: Lowell Observatory
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2026-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2305225&HistoricalAwards=false
• 关键词: Collaborative; Research; Weirdest; Stars; Universe

Some of the weirdest stars in the universe are called Thorne-Zytkow objects, or TZOs. They represent a completely new model for how the insides of stars can work, a new possible fate for binary star systems, and a new way to produce heavy elements. This research program will carry out an in-depth study of TZOs. The investigators will run computer simulations of the binary star systems that might form TZOs and use some of the planet's largest telescopes to search for TZOs. In addition to learning more about these mysterious stars, this research will transform our understanding of cold and massive stars and explain how they evolve, die, and enrich the chemistry of our universe. The investigators will work closely with high school students on short research projects that can be presented at regional or state science fairs. Thorne-Zytkow objects combine the outward appearance of red supergiants - cold and luminous massive stars - with strange neutron cores supported not by standard stellar fusion, but by extreme quantum physics. The formation and evolution of a TZOs is key for understanding this novel model of supporting a cool luminous exterior with a neutron degenerate interior. Terminal TZO scenarios, which could include mass-loss-driven dissipation of their outer layers, a supernova-like explosion, or direct collapse to a black hole, are crucial for understanding how TZOs contribute to enrichment and add to the population of compact objects. The merger of a red supergiant and neutron star to form a TZO is notably different from the standard scenario assumed for massive binaries, where both stars produce compact objects and eventually merge to generate a gravitational wave transient. Neglecting TZO formation and evolution will lead to incorrect predictions for heavy element enrichment and an over-prediction of gravitational wave transients. Using high-resolution spectroscopy, advanced stellar atmosphere models tailored for cool stars, and archival light curves of these stars, the investigators will determine whether potential TZO candidates have the distinctive surface abundance signatures predicted. As an integral part of this research program, the investigators will work annually with high school students on short research projects suitable for presentation at regional or state science fairs and develop infrastructure for use by other potential project mentors across the field of astronomy.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

宇宙中一些最奇怪的恒星被称为索恩-齐特科天体，或 TZO。它们代表了恒星内部如何运作的全新模型、双星系统的新可能命运以及产生重元素的新方法。该研究计划将对TZO进行深入研究。研究人员将对可能形成 TZO 的双星系统进行计算机模拟，并使用地球上一些最大的望远镜来寻找 TZO。除了更多地了解这些神秘恒星之外，这项研究还将改变我们对寒冷和大质量恒星的理解，并解释它们如何演化、死亡和丰富宇宙的化学成分。研究人员将与高中生密切合作，开展短期研究项目，这些项目可以在地区或州科学博览会上展示。索恩-齐特科天体将红超巨星（寒冷而明亮的大质量恒星）的外观与奇怪的中子核心结合在一起，这些中子核心不是由标准恒星聚变支持，而是由极端量子物理学支持。 TZO 的形成和演化是理解这种支持冷发光外部和中子简并内部的新颖模型的关键。终端 TZO 场景可能包括质量损失驱动的外层耗散、超新星般的爆炸或直接塌缩成黑洞，这些对于理解 TZO 如何促进致密天体浓缩和增加致密天体数量至关重要。红超巨星和中子星合并形成 TZO 与大质量双星假设的标准场景明显不同，在标准场景中，两颗恒星都会产生致密天体，并最终合并产生瞬态引力波。忽视TZO的形成和演化将导致对重元素富集的错误预测和对引力波瞬变的过度预测。研究人员将利用高分辨率光谱、为冷恒星量身定制的先进恒星大气模型以及这些恒星的档案光曲线，确定潜在的 TZO 候选者是否具有预测的独特表面丰度特征。作为该研究计划的一个组成部分，研究人员每年将与高中生合作开展适合在地区或州科学博览会上展示的短期研究项目，并开发基础设施供天文学领域其他潜在项目导师使用。该奖项反映了通过使用基金会的智力价值和更广泛的影响审查标准进行评估，NSF 的法定使命被认为值得支持。