Abstract The first complete light curves of two eclipsing binaries in Camelopardalis, NX Cam and V584 Cam, are here presented together with the new observations of the system NSVS 2643686 obtained in 2014. The light curves were modelled using the latest version of the Wilson-Devinney code. Our results show that all the three systems have an extreme mass ratio q 50%, belong to the class of the so called Deep Low Mass Ratio systems (DLMR) but show different physical characteristics. The two above systems are totally eclipsed binaries with the duration of the secondary eclipse of 87 min for NX Cam and 51 min for NSVS 2643686. The other system, V584 Cam, shows a middle fill-out value of f = 33% and low inclination. Using our Times of Minima (ToM) derived from the observations as well as those found in the literature, the ephemerides of the three systems are here revised. The absolute dimensions are estimated and, from statistical diagram, it is found that all the components of the systems follow the general pattern of the well known W UMa contact binaries.

中文翻译：

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三接触二元系统的光度学研究

摘要 这里展示了鹿豹座中两个食双星 NX Cam 和 V584 Cam 的第一个完整光变曲线，以及 2014 年获得的 NSVS 2643686 系统的新观测结果。光变曲线是使用最新版本的 Wilson-Devinney代码。我们的结果表明，所有三个系统都具有 50% 的极端质量比，属于所谓的深低质量比系统 (DLMR)，但显示出不同的物理特性。上述两个系统是完全重叠的二进制文件，NX Cam 的二次日食持续时间为 87 分钟，NSVS 2643686 的二次日食持续时间为 51 分钟。另一个系统 V584 Cam 显示 f = 33% 的中间填充值和低倾角. 使用我们从观察结果以及文献中发现的最小值（ToM）得出的时间，三个系统的星历在此修改。估计绝对尺寸，并且从统计图中发现系统的所有组件都遵循众所周知的 W UMa 接触二进制的一般模式。