Stellar Atmospheric Stratification Measured by Millisecond Spectrophotometry of Lunar Occultations

通过掩月毫秒分光光度法测量恒星大气层结

• 批准号: 8820542
• 负责人: Nathaniel White
• 金额: --
• 依托单位: Lowell Observatory
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-05-01 至 1991-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8820542&HistoricalAwards=false
• 关键词: Stellar; Atmospheric; Stratification; Measured; Millisecond

As radiant energy diffuses from a star's interior through its surface layers, it interacts with the constituent gases --atoms, ions, and molecules -- in those surface layers and produces a host of absorption and emission lines. These lines constitute a signature that is accessible to terrestrial observation and analysis, telling us a great deal about the temperature, density, and composition structure of stellar atmospheres. This is a particularly rich field of study in the case of cool giant stars, for their light is characterized by an abundance of spectral lines. The Principal Investigator (PI) proposes to use millisecond time resolution spectrophotometry in the observation of cool, bright giant stars during lunar occultations. The goal is to measure the mean depths of the formation of spectral features in the extended atmospheres of these stars and in the inner layers of the dust shells surrounding some of them. Furthermore, the PI will measure the angular diameters of these stars and derive the dependence of angular diameter on absorption features and the stars' colors.

当辐射能量从星星内部扩散到表面层时，它与表面层中的组成气体原子、离子和分子相互作用，产生大量的吸收和发射线。这些谱线构成了一个可用于地面观测和分析的特征，告诉我们大量关于恒星大气的温度、密度和组成结构的信息。对于冷巨星来说，这是一个特别丰富的研究领域，因为它们的光具有丰富的光谱线。首席研究员（PI）建议在月掩期间使用毫秒时间分辨率分光光度法观测冷而明亮的巨星。目标是测量这些恒星的扩展大气层和其中一些恒星周围尘埃壳内层光谱特征形成的平均深度。此外，PI将测量这些恒星的角直径，并推导出角直径对吸收特征和恒星颜色的依赖关系。