摘要
利用我们观测得到的57个RS CVn型双星的高分辨(0.049A—0.145()),高信噪比(100—600)的Reticon和CCD光谱测定了金属锂(Li)的丰度并采用大气模型综合分析方法对其中10个双星计算了金属丰度[Fe/H],[Ti/Fe],[Li/Fe]和logN(Li).本文统计分析了这类双星锂的丰度与有效温度T_(eff),及锂的丰度与自转速度在视线方向投影ν sin i的相关性.结果表明:恒星大气中锂的丰度随着有效温度的降低而趋向减少,另一方面锂的丰度随着ν sin i的增大也有减少的趋势,但弥散很大,特别是在ν sin i<25公里/秒范围的星,可以说不相关.统计分析还表明这57个RS CVn型双星(包括76个可探测到的子星)其锂的丰度和活动性的强弱无明显关系.但是值得注意的是在7个双星系统中冷子星为活动性较强时,其锂的丰度皆低于它的活动性差些的热子星,相反的情况没有看到。
High-resolution (0.049A—0.145A), high signal-to-noise ratio(100—600) spectral of 57 RS CVn type binaries, which were observed with the coudé spectrographs of the Mcdonald 2.1m telescope and the Yunnan 1 m telescope were used to analyse the correlation between Li abundance and Chromospheric activity. Li abundance of 57 RS CVn systems, Which include 87 detected components, has been determined through the determination of equivalent widths of Li doublet (6707.761A+6707.912A) and by using Kurucz's (1979) model atmosphere. The model metal abundance and line analysis of 10 RS CVn stars were determined from the present spectral lines data. The main results are the followings: 1, Lithium abundances of 87 RS CVn componets for 57 RS CVn systems is obviously reduced with the effective temperature gradual decreasing. 2, Li abundance has a statistically descescent trends in RS CVn stars with the rotational velocities vsini increasing. 3, The locus of RS CVn stars in the (U-B, B-V) Figure shows that 168 RS CVn systems can be divided into two groups. The most of them are unlikly to be poor-metal stars. Li abundance of RSCVN stars seems have no obvious correlation with the chromospheric activity. However, there are 7 RS CVn systems in which the cool components are more active built poorer in Li abundance than their hot components are.
出处
《天文学报》
CSCD
北大核心
1992年第3期316-326,共11页
Acta Astronomica Sinica
关键词
RSCVn型
双星
色球活动
锂
丰度
RSCVN type binaries—Chromospherically active—Lithium abundance
