X　Per的新发射相：光谱与红外观测

RECENT EMISSION PHASE IN X PER: SPECTROSCOPIC AND INFRARED OBSERVATIONS

ＸＰｅｒ的新发射相：光谱与红外观测杭恒荣，夏剑萍中国科学院紫金山天文台，南京２１０００８中国科学院光学天文联合实验室关键词Ｂｅ星／Ｘ射线双星，发射线，ＪＨＫ测光１引言ＸＰｅｒ是一颗Ｂｅ／Ｘ射线双星（４Ｕ０３５２＋３０）的光学对应体［１－３］，中子星的...

We have been monitoring a number of Be/X-ray binaries, such as X Per, using optical spectroscopy and JHK photometry since 1992. It was reported, that in mid1990 X Per underwent a dramatic phase change, losing its circumstellar shell, infrared excess and H-alpha emission line,and the optical minimum lasted from 1989 until at least early 1992. Our measurements show that a new emission phase in X Per has been developing at least since 29th Octorber 1992. From late 1992 to early 1995, the equivalent widths of H-alpha emission line were about 1.0A in the Autuinn of 1992, and increased gradually to reach more than 12A in Feb. 1995. The infrared magnitudes of JHK were also brightening in this period,being about 6.5 in November 1992 and reach 5.2 in September 1994 in K band. Fig. 1 and Fig. 2 show the variations of the equivalent width of H-alpha emission line and infrared magnitudes of J, H and K with time. Fig. 3 and Fig. 4 show the variations of normalized line profiles of H-alpha and Hel 6678A. From the variations of both H-alpha and HeI 6678A line profiles, we can see that when the emission lines increased,the increments were only central parts of the lines between two emission peaks, and the distances between two peaks were reduced gradually. In view of the facts metioned above we suggest that a new circuilistellar shell around X Per was formed and gradually inflated between these years.