论文标题
ASAS J174406+2446.8被识别为边缘接触二进制
ASAS J174406+2446.8 is identified as a marginal-contact binary with a possible cool third body
论文作者
论文摘要
ASAS J174406+2446.8最初被发现为$δ$ scuti-Type脉动星,该周期为p = 0.189068 $ days $ by ASAS调查。但是,Lamost恒星参数表明,它远远超出了$ \ log g-t $ scuti脉动脉冲星的脉冲不稳定条的红色边缘。为了了解变量恒星的物理特性,我们通过反射云南天文台的望远镜的1.0 m cassegrain观察到它。获得了B,V,R $ _ {C} $中的多色光曲线,并获得了i $ _ {C} $ bands,并使用W-D程序进行分析。发现该变量恒星是具有EB型光曲线的浅触发二进制,轨道周期为0.3781 \,而不是$δ$ scuti star。这是W-SubType触点二进制文件,质量比为$ 1.135(\ pm0.019)$,填充因子为$ 10.4(\ pm5.6)\,\%$。 ASAS J174406+2446.8的情况类似于其他EB型边际接触二进制物,例如UU Lyn,II和GW Tau。它们都处于关键进化阶段,从半独立式构型到由热弛豫振荡理论预测的接触系统。通过使用303个新确定的光最小值时间来校正线性胚片。可以检测到O-C曲线显示正弦变异,可以通过存在凉爽的红色矮人来解释光轨道时间的效应。本研究表明,$ \ \ log g-t $ g-t $图上的$δ$ scuti型恒星超出了脉动不稳定带的红色边缘,这是错误分类的折叠二进制文件。要了解其结构和进化状态,将来需要更多的研究。
ASAS J174406+2446.8 was originally found as a $δ$ Scuti-type pulsating star with the period P=0.189068 $days$ by ASAS survey. However, the LAMOST stellar parameters reveal that it is far beyond the red edge of pulsational instability strip on the $\log g-T$ diagram of $δ$ Scuti pulsating stars. To understand the physical properties of the variable star, we observed it by the 1.0-m Cassegrain reflecting telescope at Yunnan Observatories. Multi-color light curves in B, V, R$_{c}$ and I$_{c}$ bands were obtained and are analyzed by using the W-D program. It is found that this variable star is a shallow-contact binary with an EB-type light curve and an orbital period of 0.3781\,days rather than a $δ$ Scuti star. It is a W-subtype contact binary with a mass ratio of $1.135(\pm0.019)$ and a fill-out factor of $10.4(\pm5.6)\,\%$. The situation of ASAS J174406+2446.8 resembles those of other EB-type marginal-contact binaries such as UU Lyn, II Per and GW Tau. All of them are at a key evolutionary phase from a semi-detached configuration to a contact system predicted by the thermal relaxation oscillation theory. The linear ephemeris was corrected by using 303 new determined times of light minimum. It is detected that the O - C curve shows a sinusoidal variationthat could be explained by the light-travel-time effect via the presence of a cool red dwarf. The present investigation reveals that some of the $δ$ Scuti-type stars beyond the red edge of pulsating instability strip on the $\log g-T$ diagram are misclassified eclipsing binaries. To understand their structures and evolutionary states, more studies are required in the future.