南方基地知识库

基于对9颗类太阳色球活动恒星高信噪比的高色散光谱观测,测量了这些恒星锂线（λ=6707.8?）的等值宽度,计算了这些恒星表层锂元素丰度.通过研究这些类太阳色球活动恒星锂丰度和X射线光度之间的关系,发现X射线光度强的类太阳色球活动恒星锂丰度值大于X射线较弱的恒星.也就是说活动性较强的类太阳色球活动恒星其锂丰度较高,活动性较弱的类太阳色球活动恒星其锂丰度较低.考虑到主序的类太阳恒星锂元素和恒星自转速度随着恒星年龄的增加逐渐减少,以及随着类太阳色球活动恒星自转速度的减小,色球活动又逐渐变弱.因此类似于锂丰度,类太阳色球活动恒星自转速度的大小和恒星的活动水平也同样可以表明恒星的年龄. 

Based on the high signal-to-noise ratio (S/N) and high-dispersion spectroscopic observations, we derived the equivalent width of the Li I  6707. 8 ˚A and the lithium abundance for 9 active late-type stars. The correlation between the lithium abundance and the X-ray luminosity (lg LX) indicates that the lithium abundance of these 9 active late-type stars with a higher X-ray luminosity tends to be larger than that of those with lower X-ray luminosity. That is to say that the lithium abundances analogs progressively increase as the activity increases for these late-type stars. Considering both the lithium abundance and the rotational velocity decreases with increasing stellar age for main-sequence stars and activity increasing with increasing rotation velocity for active late-type stars, like lithium abundance, the rotational velocity and stellar activity are also considered good indicators of age for late-type stars.