【摘要】 文中给出了我们于1988年和1989年间用32/385cm折光望远镜及60/90/180cm Schmidt照相仪对行星状星云核星V651Mon.的照相光度观测结果。从V651Mon.的光变曲线中我们看到,已于1987年趋于消失的食光变现象(其光度起伏△m～0.~m4),到1988年重又出现,其光变幅增大到△m～1.~m1。且其食变参数与1986年各有差异.同时从1989年的观测结果中也证实了这种现象的存在.对此,文中也进行了初步分析讨论.更多还原

【Abstract】 In this paper we present the photographic photometry, of V651 Mon during 1988—1989. The observations are given in Table 1 and the parameters of the light curves of V651 Mon are given in Table. 2 The photographic light curves we obtained in 1988 and 1989 are plotted in Figure 1. From these observations we find that the brightness variations of V651 Mon changed substantially from 1987 to 1988. The eclipse amplitude changed from about 0.4 mag. （1987） to 1.1 mag. （1988）. And the "eclipse" variations in the light curve appeared again in 1988 and the "eclipse" roughly lasted 40% of the orbital period. The maximum brightness (m_pq) in 1988 was brighter than that in 1987. From the observations of 1989 it can be stated that the "eclipse" event still existed in 1989. From these it is reasonable to think that the binary central star of planetary nebula V651 Mon might undergo another mass ejection from the subdwarf O component during 1987—1988.更多还原