论文标题
关于大规模互动二进制UU Cassiopeiae的新见解
New insights on the massive interacting binary UU Cassiopeiae
论文作者
论文摘要
我们介绍了基于先前发表的多波长光度和光谱数据的近二元UU Cassiopeiae的研究结果。基于过去117年的日食时间，我们发现$ \ rm p_ {o} = 8.519296（8）$ d的改进的轨道周期。此外，我们在$ i_c $ -band数据中找到了长度$ t $ $ \ sim $ 270 d的长周期。没有证据表明上个世纪的轨道时期变化，这表明系统中质量损失的速度或恒星之间的质量交换应该很小。在整个轨道循环中检测到零星和快速亮度下降到$δ$ = 0.3 mag的降低，红外光度法清楚地表明存在情节物质。我们对11个已发表数据集的轨道光曲线进行建模，以固定以前的光谱工作的质量比和凉爽的恒星温度。 $ q $ = 0.52和$ t_c $ = 22 700 k。我们找到一个以74度的角度看到的系统，恒星分离为52 $ {\ rm r _ {\ odot}} $，热量较高的星级$ t_h $ = 30 200 $ k $ k $ t_h $ = 30 200 $ k $ 17.4和9 $} 7.0和16.9 $ {\ rm r _ {\ odot}} $和表面重力log g = 3.98和2.94，分别为热和冷却器的星。我们发现围绕较大恒星的积聚盘，半径为21 $ {\ rm r _ {\ odot}} $，其外边缘的垂直厚度为6.5 $ {\ rm r _ {\ odot}} $，最大的是掩盖热星。发现两个比周围磁盘更热的活动区域，一个大致位于预期位置，该磁盘会影响磁盘，另一个位于磁盘另一侧。在不同数据集中的磁盘和斑点参数中观察到变化。
We present the results of the study of the close binary UU Cassiopeiae based on previously published multi wavelength photometric and spectroscopic data. Based on eclipse timings of the last 117 years, we find an improved orbital period of $\rm P_{o} = 8.519296(8)$ d. In addition, we find a long cycle of length $T$ $\sim$ 270 d in the $I_c$-band data. There is no evidence for orbital period change during the last century, suggesting that the rate of mass loss from the system or mass exchange between the stars should be small. Sporadic and rapid brightness drops of up to $Δ$$V$ = 0.3 mag are detected during the whole orbital cycle and infrared photometry clearly suggests the presence of circumstellar matter. We model the orbital light curve of 11 published datasets fixing the mass ratio and cool star temperature from previous spectroscopic work; $q$= 0.52 and $T_c$= 22 700 K. We find a system seen at angle 74 degrees with a stellar separation of 52 ${\rm R_{\odot}}$, a temperature for the hotter star $T_h$= 30 200 $K$ and stellar masses 17.4 and 9 ${\rm M_{\odot}}$ , radii 7.0 and 16.9 ${\rm R_{\odot}}$ and surface gravities log g = 3.98 and 2.94, for the hotter and cooler star, respectively. We find an accretion disk surrounding the more massive star, with a radius of 21 ${\rm R_{\odot}}$ and vertical thickness in its outer edge of 6.5 ${\rm R_{\odot}}$, mostly occulting the hotter star. Two active regions hotter than the surrounding disk are found, one located roughly in the expected position where the stream impacts the disk and the other one in the opposite side of the disk. Changes are observed in parameters of the disk and spots in different datasets.
