摘要
本文讨论了现有的两个恒星自转测量标准系统:Slettebak老系统及新系统之间的系统差,给出了两系统间的回归关系及回归系数的误差估计.结果表明:两系统间存在显著系统差,而所用的方法模型、观测技术之间的差异不可能引起如此大的系统差. 本文的另一个有趣结果是:尽管恒星自转达到其临界值的0.9倍,而旋转所引起的形状畸变、引力昏暗等效应对谱线半宽法的自转速度测量值的影响仍在4%左右;但当恒星以临界速度旋转时,以上自转效应的忽略将使谱线半宽法的实测值大大降低.对B型星,这些效应的影响可达30%.
We estimate the systematic differences between Slettebak 'old' and 'new' systems of stellar rotational velocities, and present the regression relation between two systems. While our estimated values of the differences are larger than earlier estimates, it seems unlikely that these differences can be attributed to the disagreements between the models of the systems, and to the discrepancy between the observational tech tiques of the two systems. Also, we discuss the influences of the rotational effects due to the shape distortion, the gravity darkening etc on the measurements of stellar rotational velocities. Those influences are important only when the fractional angular velocity of the star, ω>0.9.
出处
《天文学报》
CSCD
北大核心
1992年第4期395-402,共8页
Acta Astronomica Sinica
基金
国家自然科学基金
关键词
恒星
自转
测量
标准
Star—Stellar rotation—Standard system
