Most Massive Stars in the Local Universe

在这里，斯坦内克博士和合作者将对本宇宙中质量最大的恒星进行系统的研究，方法是在银河系、本星系群、甚至本星系群之外的一些星系中探测和观察它们的食双星。该策略包括通过光度变异性调查来发现食双星，从中选择最亮、质量最大的候选星进行光谱跟踪。目标是找到并测量这些食双星中质量最大的恒星的准确参数，特别是那些在附近的星系中，重元素丰度高低都有。研究人员已经开始监测几个年轻的星系团，并获得了本星系群（LMC， SMC， M31和M33）中明亮的食双星的后续光谱。该研究计划预计将为在各种环境中发现的数十颗大质量恒星提供准确的基本参数（特别是质量和半径），并将为测试恒星大气模型、风模型、单星和双星的恒星演化模型提供数据，作为组成的函数，以及对恒星质量上限的理论预测。此外，它将提供早期型接触双星和双星分数的统计数据，从而约束大质量恒星形成模型，并通过逃逸的OB双星了解疏散星团的演化。作为副产品，许多新的变星也将被发现。最后，研究质量最大的恒星将使人们对高质量x射线双星的祖先、核心坍缩超新星、超新星与伽马射线爆发之间的联系以及III星族恒星有新的认识。其中很大一部分工作将由一名研究生和一名博士后进行，为前沿科学研究提供广泛的培训。该项目的成果将在同行评议的期刊、会议记录、大众报刊和网络上广泛传播。所有收集到的数据和结果将通过一个公共WWW网站免费提供，以便为该领域的其他工作人员以及天文学教育者提供全面访问这些遗留质量数据的机会。

Here Dr. Stanek and collaborators will undertake a systematic study of the most massive stars in the Local Universe, by detecting and observing them in eclipsing binaries in the Milky Way, in Local Group galaxies, and even in some galaxies beyond the Local Group. The strategy involves discovering eclipsing binaries via photometric variability surveys, from which the brightest and thus most massive candidates are selected for spectroscopic follow-up. The goal is to find and measure accurate parameters of the most massive stars in these eclipsing binaries, especially those in nearby galaxies with both high and low abundances of heavy elements. The investigators have already begun monitoring several young Galactic clusters and obtaining follow up spectroscopy of bright eclipsing binaries in Local Group galaxies (LMC, SMC, M31, and M33).The research program is expected to yield accurate fundamental parameters (notably masses and radii) for dozens of massive stars discovered in a variety of environments, and will provide data with which to test stellar atmosphere models, wind models, stellar evolution models for both single and binary stars as a function of composition and the theoretical predictions on the upper limit of the stellar mass. Additionally, it will provide statistics on early-type contact binaries and the binary fraction, thus constraining massive star formation models, and insight into the evolution of open clusters via runaway OB stars that are binaries. As a side product, many new variable stars will also be discovered. Finally, studying the most massive stars will allow new insights into the progenitors of high-mass X-ray binaries, core-collapse supernovae, the connection between supernovae and gamma-ray bursts, and Population III stars.A significant part of the proposed work will be carried out by a graduate student and a postdoctoral researcher, providing extensive training in cutting-edge scientific research. Results from this project will be broadly disseminated by publication in peer reviewed journals, conference proceedings, the popular press and the Web. All the gathered data and results will be freely available via a public WWW site, as to provide other workers in this field, as well as astronomy educators, with full access to these legacy-quality data.