IR Studies of the Circumstellar Environs of Evolved Stars

演化恒星星周环境的红外研究

• 批准号: 0205814
• 负责人: Charles Woodward
• 金额: $ 25.1万
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-07-01 至 2006-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0205814&HistoricalAwards=false
• 关键词: IR; Studies; Circumstellar; Environs; Evolved

AST-0205814PI WoodwardThe interstellar medium is enriched with chemical elements synthesized in the interiors of stars and dust grains formed in their atmospheres. Stars accomplish this enrichment through mass outflows ranging in character from slow winds in post-main sequence, luminous evolved stars that operate over long time scales, to explosive events such as novae. By observing these outflows the process of chemical enrichment can be investigated. In particular IR observations will be carried out to provide abundance estimates for elements in the ejecta, such as C, N, O, Ne, Mg, Al, and Si, that can be used to assess the contributions of stellar winds to the interstellar medium. For a nova event prompt observations of sudden, transient activity at many wavelengths are required. This study will provide information about the stages of stellar evolution that are associated with mass loss, characterize the physical properties of astrophysical dust grains in circumstellar outflows, and assess the contributions that novae and luminous IR variable stars make to the grains and gas that constitute the interstellar medium. ***

AST-0205814PI Woodward星际介质富含恒星内部合成的化学元素和大气中形成的尘埃颗粒。 恒星通过质量外流来实现这种富集，其特征包括后主序带中的慢风、长时间运行的发光演化恒星，以及新星等爆炸事件。通过观察这些流出物，可以研究化学富集的过程。特别是，将进行红外观测，以提供喷射物中元素的丰度估计，例如碳、氮、氧、氖、镁、铝和硅，这些元素可用于评估恒星风对星际介质的贡献。对于新星事件，需要在许多波长下观察突然、瞬态的活动。 这项研究将提供与质量损失相关的恒星演化阶段的信息，表征星际外流中天体物理尘埃颗粒的物理特性，并评估新星和发光红外变星对构成星际介质的颗粒和气体的贡献。 ***