Rapid Variability in the Spectral Lines of Be Stars

Be星光谱线的快速变化

• 批准号: 8917740
• 负责人: Douglas Gies
• 金额: $ 2.96万
• 依托单位: Georgia State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-09-15 至 1991-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8917740&HistoricalAwards=false
• 关键词: Rapid; Variability; Spectral; Lines; Stars

Stars have wide ranges of masses, ages, rotation rates, and other physical properties. For example, Be stars are relatively young, rapidly rotating stars of type B, with surface temperatures above 10,000 K and characteristic emission features (hence, the "e" in Be) in their hydrogen Balmer lines. During the last few years, photometric and spectroscopic observations have revealed variations in the colors and in the absorption lines of Be stars that move from the blue to the red, on time scales of 0.2 to 2 days, and that so far have defied unique physical explanation. Vogt and Penrod have interpreted these variations as being due to nonradial pulsations (NRPs) in the stars' photospheres. The PI will test the NRP model with a time series analysis of the stars' absorption line variations. Furthermore, he will compare variations in the stars' photospheres, circumstellar disks, and high velocity winds to determine whether the proposed NRPs are responsible for the mass loss observed from these and, possibly, other rapidly rotating stars.

恒星的质量、年龄、自转速率和其他参数都有很大的变化。 物理性质 例如，Be恒星相对年轻， 快速旋转的B型恒星，表面温度高于 10，000 K和特征发射特征（因此， 是）在他们的氢巴尔默线。 在过去的几年里， 光度和光谱观测揭示了 Be星的颜色和吸收线 从蓝色到红色，时间尺度为0.2到2天， 至今仍无法用物理学解释 沃格特和彭罗德解释说，这些变化是由于 恒星光球层中的非径向脉动（NRP）。 的pi 将通过对恒星的时间序列分析来测试NRP模型， 吸收线变化。 此外，他将比较 恒星光球层、星周盘和 高速风，以确定是否建议NRPs是 负责从这些观察到的质量损失，可能， 其他快速旋转的恒星