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

宇宙中一些最奇怪的恒星被称为索恩-齐特科夫天体，或TZO。它们代表了恒星内部如何工作的全新模型，双星系统可能的新命运，以及产生重元素的新方法。本研究项目将对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搜索TZO。除了了解更多关于这些神秘恒星的信息，这项研究还将改变我们对冷恒星和大质量恒星的理解，并解释它们是如何演化、死亡和丰富我们宇宙的化学物质的。研究人员将与高中生密切合作，开展简短的研究项目，这些项目可以在地区或州的科学博览会上展示。索恩-齐特科夫天体将红色超巨星--寒冷而明亮的大质量恒星--的外观与奇怪的中子核结合在一起，这些中子核不是由标准的恒星聚变支持的，而是由极端量子物理支持的。TZO的形成和演化是理解这种以中子简并内部支撑冷光外部的新模型的关键。末期TZO的情景，可能包括外层质量损失驱动的消散、类似超新星的爆炸，或者直接坍塌到黑洞，对于理解TZO如何有助于浓缩和增加致密天体的数量至关重要。红色超巨星和中子星合并形成TZO与大质量双星的标准假设有显著不同，在标准情况下，两颗恒星都会产生致密物体，并最终合并产生引力波瞬变。忽视TZO的形成和演化将导致对重元素丰度的错误预测和对引力波瞬变的过度预测。使用高分辨率光谱学，为冷星量身定做的高级恒星大气模型，以及这些恒星的档案光曲线，研究人员将确定潜在的TZO候选者是否具有预测的独特的表面丰度特征。作为这一研究计划的组成部分，研究人员将每年与高中生合作开展适合在地区或州科学博览会上展示的简短研究项目，并开发基础设施，供天文学领域其他潜在的项目导师使用。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

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.