Infrared Studies of Transient Events: Classical Novae and Variable Stars

瞬变事件的红外研究：经典新星和变星

• 批准号: 9528336
• 负责人: Robert Gehrz
• 金额: $ 30.63万
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-07-01 至 2001-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9528336&HistoricalAwards=false
• 关键词: Infrared; Studies; Transient; Events; Classical

Gehrz, Robert 95-28336 Classical novae and luminous evolved (post main sequence) stars are important sources of processed material that is recycled to the interstellar medium (ISM) in circumstellar outflows during stellar evolution. Quantitative information about the dust and gas ejected in these outflows is necessary to provide fundamental constraints on models of Galactic chemical evolution. Infrared (IR) photometry and spectroscopy are particularly powerful tools for evaluating the abundances of both solid and gaseous phases of circumstellar material. IR spectrophotometry, imaging and polarimetry can be used to deduce the physical characteristics of the circumstellar outflows and of the grains that form within them. A three year extension is planned to the University of Minnesota IR group's program to study circumstellar dust and gas through IR observations of the temporal development of classical nova explosions and the transient activity of luminous IR variable stars. The studies will characterize the nucleation and growth of astrophysical dust grains in circumstellar outflows, asses the contributions of solid and gas-phase matter that novae and IR variable stars make to the ISM, and provide information about the stages of stellar evolution that preceded the mass loss process. Successful fulfillment of many of the program objectives requires prompt observations of sudden, transient activity at many wavelengths. The study will build upon previous observations and will benefit from their capabilities to obtain timely, remote and simultaneous multi-wavelength observations of transient events with telescopes in Minnesota, Wyoming and Arizona. ***

Gehrz，Robert 95-28336 经典新星和发光演化（后主序星）恒星是重要的加工材料的来源，这些材料在恒星演化过程中以星周流出物的形式再循环到星际介质（ISM）。 在这些外流中喷出的尘埃和气体的定量信息是必要的，以提供银河系化学演化模型的基本约束。 红外测光和光谱学是评估星周物质的固相和气相丰度的特别有力的工具。 红外分光光度法、成像法和偏振法可以用来推断出星周流出物和其中形成的颗粒的物理特性。 计划将明尼苏达大学红外小组的方案延长三年，通过对经典新星爆炸的时间发展和发光红外变星的瞬时活动进行红外观测，研究星周尘埃和气体。 这些研究将描述星周外流中天体物理尘埃颗粒的成核和生长，评估新星和红外变星对ISM的固态和气相物质的贡献，并提供有关质量损失过程之前恒星演化阶段的信息。 许多计划目标的成功实现需要在许多波长上对突然的瞬态活动进行及时观测。 这项研究将建立在以前的观测基础上，并将受益于它们利用明尼苏达州、怀俄明州和亚利桑那州的望远镜对瞬变事件进行及时、远程和同时多波长观测的能力。 ***