Abstract

Contact binary systems are very important for studying physical processes such as strong interactions between stars, mass transfer, and stellar merger. Further, the members of an open cluster have the same age, metal abundance, and interstellar extinction conditions. Therefore, we can conduct a comparative study on the different binary systems of the same open cluster. NGC 6811 is an observed intermediate-aged, slightly reddened open cluster in the Kepler field of view; we conducted a corresponding study on the contact binary systems in this cluster. We analyzed six suspected targets and found a total of five EW-type binary systems within a field of 40′ radius of the NGC 6811 cluster center. These targets were analyzed base on the Kepler data, and the corresponding system parameters were obtained by using the latest version of the Wilson–Devinney code. Further, we also used Gaia DR2 data and the cluster distance data to estimate the absolute parameters of these targets to determine whether they are members of the cluster. Finally, we determined that two targets (KIC 9470175 and KIC 9533706) are most likely cluster members; KIC 9957411 and KIC 9776718 are definitely not members of the cluster, just background stars.

中文翻译：

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NGC 6811领域中的接触二元研究

摘要

接触二元系统对于研究物理过程（例如恒星之间的强相互作用，传质和恒星合并）非常重要。此外，开放星团的成员具有相同的年龄，金属丰度和星际灭绝条件。因此，我们可以对同一开放集群的不同二进制系统进行比较研究。NGC 6811是在开普勒视野中观察到的中年，略微发红的疏散星团；我们对该集群中的接触二元系统进行了相应的研究。我们分析了六个可疑目标，并在NGC 6811团簇中心的40'半径范围内发现了总共五个EW型二元系统。根据开普勒数据对这些目标进行了分析，通过使用最新版本的Wilson-Devinney代码获得相应的系统参数。此外，我们还使用Gaia DR2数据和聚类距离数据来估计这些目标的绝对参数，以确定它们是否是聚类的成员。最后，我们确定两个目标（KIC 9470175和KIC 9533706）是最有可能的集群成员。KIC 9957411和KIC 9776718绝对不是集群的成员，而只是背景恒星。