Spectral Classification of Hot Subdwarfs

热亚矮星的光谱分类

• 批准号: 9819835
• 负责人: John Drilling
• 金额: $ 10万
• 依托单位: Louisiana State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-06-15 至 2005-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9819835&HistoricalAwards=false
• 关键词: Spectral; Classification; Hot; Subdwarfs

ABSTRACTDrilling, John"Spectral Classification of Hot Subdwarfs"AST-9819835A system for classifying the spectra of rare but astrophysically important hot stars called subdwarfs has been developed. Such luminous stars are important clues to stellar evolution and provide valuable distance and age indices for studies of star clusters in the Galaxy. It has been found that three parameters are necessary to uniquely classify such stars: temperature, luminosity and "helium abundance." This project will refine and complete the basic system of classification. Particular attention will be paid to what appears to be two "parallel spectral sequences" that depend upon whether a star exhibits strong lines of carbon (CII, CIII or CIV), that are thought to be an index for He abundance. A calibration of the new spectral types with effective temperature, surface gravity, luminosity, photometric color and helium abundance will be derived and an attempt will be made to draw connections between these spectral types and the groups of hot subdwarfs identified during the Palomar-Green survey.

AST-9819835A系统，用于对稀有但具有天体重要的热星的光谱进行分类，称为SubdWarfs。 这种发光的恒星是恒星进化的重要线索，并为星系中的恒星簇研究提供了宝贵的距离和年龄指数。 已经发现，要唯一对此类恒星进行唯一分类是必要的三个参数：温度，光度和“氦气丰度”。 该项目将完善并完成基本的分类系统。 特别关注似乎是两个“平行光谱序列”，这些序列取决于恒星是否表现出强的碳（CII，CIII或CIV），它们被认为是他丰富的指数。 将得出具有有效温度，表面重力，发光度，光度颜色和氦气丰度的新光谱类型的校准，并将尝试在这些光谱类型和在Palomar-Green调查中识别的热分子群之间建立连接。