Mixing, Metallicity, and Binaries on the Blue Horizontal Branch

蓝色水平分支上的混合、金属丰度和二元星

• 批准号: 0098725
• 负责人: Ruth Peterson
• 金额: --
• 依托单位: Astrophysical Advances
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-06-01 至 2004-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0098725&HistoricalAwards=false
• 关键词: Mixing; Metallicity; Binaries; Blue; Horizontal

"Mixing, Metallicity, and Binaries on the Blue Horizontal Branch"AST-0098725Many changes happen to a star in the late stages of its evolution. With this award, the PI seeks to unravel the effects of deep interior mixing, mass loss, mass exchange and diffusion on the atmospheric abundances of blue horizontal branch stars. It has long been known that the blue horizontal branch can take on a very different appearance in globular clusters which seem at first sight to be very similar chemically. Strongest emphasis in the forthcoming work will be given to investigating the role of deep helium mixing and its causes. Work to date shows evidence that it does occur in two cases, in NGC6752 blue horizontal branch star which are cool enough for their atmospheres not to be influenced by diffusion, and in single extended horizontal branch stars which show C,N,O abundances that are correlated in the same way as in giant stars and are thus expected to have resulted from deep mixing. However, to reinforce this case, blue stars covering a much larger range of temperature are to be observed.

“在蓝色水平分支上的混合，金属性和二进制物” AST-0098725经济变化发生在其演变后期的恒星中。通过此奖项，PI试图揭示深内部混合，质量损失，质量交换和扩散对蓝色水平分支星星大气丰度的影响。长期以来，众所周知，蓝色的水平分支在球状簇中的外观截然不同，这似乎是化学上非常相似的。在即将到来的工作中最强调的是研究深氦混合及其原因的作用。迄今为止的工作表明，在两种情况下，在NGC6752蓝色水平分支星中确实发生了证据，它们足够凉爽，足以使它们的大气不受扩散影响，并且在单个扩展的水平分支星星中，显示出C，n，o与巨型恒星相同的丰度与巨型恒星相关，因此预计会导致深层混合。但是，为了加强这种情况，将观察到覆盖温度范围更大的蓝色星星。