1984年2月14日大角星色球活动的CaⅡ H,K线观测

我们用云台一米望远镜Coudé摄谱仪得到大量的大角星(αBoo)的高分辨率光谱,从中找到1984年2月14日一组随时间变化的CallH,K线光谱。经对比分析,我们认为这可能是一次大角星的色球爆发,其特征如下:在连续观测近四小时中获得5张光谱片,可看出CallH,K线轮廓的变化。它们变化的顺序是:开始出现轮廓的不对称一轮廓仍然不对称并伴随着峰值发射增强一轮廓恢复到对称状况;K_2线中K_(2V)与K_(2r)最大不对称为20％。发射极大时K_(2S2)峰值增强20％左右。K_(1r)和K_(1V)的变化也明显。特别是K_3线在K_2线峰值增强时出现吸收线反转出发射线核。

Chromospheric Activity of Arcturus Observed at Call H and K Lines on February 14, 1984

In 1983-1984 we obtained some high-resolution spectra of Arcturus with the Coude spec-trograph attached to the 1 m telescope at Yunnan Observatory (dispersion: 6.02 A/mm, IIa-O plates). Their Call H and K lines are compared and analysed. Five successive spectra of Arcturus observed within about four hours on Feb. 14, 1984, showed interesting variation. We think it is possible that we had been observing a flare like eruption event on Arcturus, The observed behaviour of the Call K line profiles on that night (the H line varied in a similar fashion) was as follows: At first it was asymmetric, then it. became asymmetric with intensified emission peaks, finally, it changed into its normal symmetric shape which is characteristic of the quiet state. The asymmetry relative to quiet region and the variation of K2 peaks are about 20%. K232 peaks are about 20% more stronger than quiet region. The variations of Kr1 and K1y are also obvious.