摘要
对XPer新发射相连续四年的光学光谱和近红外光度监测表明，XPer近两年的变化不同寻常，主要表现在以下两点：（1）尽管它的光学光度V星等只恢复到失去气壳前的亮度，但Hα发射线等值宽度和近红外J、H和K光度却超过了历史记录的最大值，分别达到16．34A和5．3m、5.3m和5.1m，表明XPer新发射相气壳的密度和尺度都较大．（2）我们首次观测到XPer近红外光度和Hα发射线等值宽度变化趋势相反的现象，在它的光学V星等和红外JHK星等达到极大值后，在开始快速下降时，Hα发射线强度和等值宽度却继续有很大的增加．我们的光谱观测支持旋转环状气壳模型，并表明气壳中存在双环结构，在双环气壳模型假设下也能较好地解释观测到的不寻常现象。
We present a series of optical spectroscopic and infrared photometric observationsof the Be / X - ray system X Per in 1992 - 95. Some phenomena in this newemission phase turn out to be unique in comparison with former observations. Firstalthough the V magnitude only recovered its original maximum brightness from 1974to 1991, the equivalent width (EW) of he emission line and JHK magnitudesexceeded the values recorded before, and this means that the circumstellar envelope ofX Per in the new emission phase is more extensive and denser. Second, we have forthe first time observed in X Per that the EW of Ha line increased rapidly while theJHK rnagnitudes declined considerably. Our optical spectroscopic data support therotating ring model of the envelope and confirm the existcnce of the double - ringstructure, with which the observed unusual phenomena may be fariy well interpreted.
出处
《天文学报》
CSCD
北大核心
1997年第4期434-440,共7页
Acta Astronomica Sinica
基金
国家自然科学基金
天文委员会资助
