Revealed by Their Own Dust: Identifying the Missing Links in Massive Star Evolution

PI和他的团队将对附近星系中的发光尘埃大质量恒星进行调查，以回答恒星演化的许多问题。 感兴趣的恒星处于大质量恒星演化的后期阶段，并且正在向环境失去质量。它们包括被称为亮蓝变星（LBV）、超巨星B[e]、一些沃尔夫-拉叶星和红超巨星的天体。这项工作的主要目标是更好地理解大质量恒星如何失去质量，特别是偶发性的，这是恒星演化理论中的一个突出的开放问题。研究人员将使用斯皮策太空望远镜的存档图像和新的地面光谱学以及光学和近红外波长的成像，为至少20个星系中的相关恒星编制颜色星等图。这些测量将被用来回答许多问题，包括：中红外过量是LBV的一个很好的标志吗？大部分是偶发性的;主要的物质抛射事件的频率是多少;所有的大质量恒星都经历这样的爆发吗？除了上述主要科学目标外，该项目将通过涉及博士后学者以及已经参与研究的研究生和本科生产生广泛的影响。此外，PI将向公众发布数据，并有一个公共宣传部分，支持每月在帕金斯天文台的公开讲座。一旦詹姆斯·韦伯太空望远镜（JWST）投入使用，该项目的结果将对天文学家具有重要的补充价值。

The PI and his team will conduct a survey of luminous dusty massive stars in nearby galaxies in order to answer many questions of stellar evolution. The stars of interest are in the late stages of massive stellar evolution and are losing mass to their environment. They include objects known as luminous blue variables (LBV), supergiant B[e], some Wolf-Rayet stars and red supergiants. The main goal of this work is to better understand how massive stars lose mass, especially episodically, is one of the outstanding open problems in stellar evolution theory. The researchers will use archived images from the Spitzer Space Telescope and new ground-based spectroscopy and imaging at optical and near-infrared wavelengths to compile color-magnitude diagrams for relevant stars in at least 20 galaxies. The measurements will be used to answer many questions, including: is a mid-infrared excess is a good marker of an LBV; is mass loss from LBV?s mostly episodic; what is the frequency of major mass ejection events; and do all massive stars undergo such outbursts? Beyond the main science goals outlined above, the project will have broad impacts by involving a postdoctoral scholar, and graduate and undergraduate students who are already involved in the research. Also, the PI will release data to the public, and has a public outreach component that supports monthly public lectures at the Perkins Observatory. Results from this project will be of significant complementary value for astronomers once James Webb Space Telescope (JWST) is operational.