Abstract We present the first CCD sets of complete light curves for two W Ursae Majoris Systems, UCAC3 276-106147 and NSVS 7377756. These light curves are here analyzed and modelled using the latest version of the Wilson-Devinney Code. We found that UCAC3 276-106147 is a W-subtype shallow-contact eclipsing binary (fill-out factor 7.5%), with a mass ratio of q = 2.88 (1/q = 0.347), a small temperature difference between the components of about ΔT =200K. NSVS 7377756 is an H-subtype binary system with a high mass ratio of q = 1.09 (1/q = 0.947), a weak degree of contact factor f = 3.8% and a temperature difference between the components of ΔT = 398 K. The light curves of both the systems appear to be unspotted. By using our 4 and 7 times of minimum light and the 30 and 104 ToMs extract from the SWASP observations, respectively for UCAC3 276-106147 and NSVS 7377756, the orbital periods are here revised. The elements obtained from this analysis are used to compute the physical parameters of the systems combining our photometric solution with the 3-D correlation obtained for contact binaries by Gazeas (2009). Based on these estimated parameters the evolutionary state of the components of the systems is investigated and discussed.

中文翻译：

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两个短周期食双星 NSVS 7377756 和 UCAC3 276-106147 的首次光度学研究

摘要 我们展示了两个 W Ursae Majoris 系统 UCAC3 276-106147 和 NSVS 7377756 的第一组 CCD 完整光变曲线。这里使用最新版本的 Wilson-Devinney Code 对这些光变曲线进行分析和建模。我们发现UCAC3 276-106147是一个W亚型浅接触食双星（填充因子7.5%），质量比q = 2.88（1/q = 0.347），各组分之间的温差很小大约 ΔT = 200K。NSVS 7377756 是一种 H 亚型二元系统，具有高质量比 q = 1.09 (1/q = 0.947)、弱接触系数 f = 3.8% 和组分之间的温差 ΔT = 398 K。两个系统的光变曲线似乎都没有斑点。通过使用我们 4 倍和 7 倍的最小光以及从 SWASP 观察中提取的 30 和 104 个 ToM，UCAC3 276-106147 和 NSVS 7377756 的轨道周期分别在这里修订。从该分析中获得的元素用于计算系统的物理参数，将我们的光度解决方案与 Gazeas (2009) 为接触二进制获得的 3-D 相关性相结合。基于这些估计参数，研究和讨论了系统组件的演化状态。