论文标题
ETA GEMINORUM：一个被延伸圆盘包围的同伴绕的绕的半毛变性星星
Eta Geminorum: An Eclipsing Semiregular Variable Star Orbited by a Companion Surrounded by an Extended Disc
论文作者
论文摘要
我们报告了M型渐近巨型分支Star ETA GEM的光谱监测11年，该恒星ETA GEM是一种半毛变量和已知的光谱二进制，周期为8.2年。我们将径向速度与文献中的其他速度相结合，以提供改进的光谱轨道溶液，提供了2979天的时间，然后我们用来预测Eclipse的过去时间。我们检查了来自业余变量观察者和其他来源的档案光度法，并找到了许多在正确时间发生的调光的实例。这证实了以前的迹象表明该系统正在黯然失色，现在它在已知时期最长的人中排名。没有看到次要的日食。 $ \ sim $ 0.4杂志持续约5个月的杂志太深了，无法由恒星伴侣产生。相反，我们建议该同伴被直径至少1.5 au的大磁盘包围，但可能更大。我们预测下一个日食的中心将发生在2029年元旦。
We report 11 yr of spectroscopic monitoring of the M-type asymptotic giant branch star eta Gem, a semiregular variable and a known spectroscopic binary with a period of 8.2 yr. We combine our radial velocities with others from the literature to provide an improved spectroscopic orbital solution giving a period of 2979 days, which we then use to predict past times of eclipse. We examine archival photometry from amateur variable star observers, and other sources, and find many instances of dimmings that occurred at the right time. This confirms previous indications that the system is eclipsing, and it now ranks among those with the longest known periods. No secondary eclipses are seen. The $\sim$0.4 mag eclipses lasting about 5 months are much too deep to be produced by a stellar companion. We propose instead that the companion is surrounded by a large disk that is at least 1.5 au in diameter, but is likely larger. We predict the center of the next eclipse will occur on New Year's day, 2029.
