Precise multi-color CCD-derived photometric data were obtained from EH Cnc at two sites during 2010, 2014 and 2018 wherein each epoch used a different instrument. This has provided a unique opportunity to investigate parameter uncertainty following Roche modeling of light curves optimized by differential corrections using the Wilson–Devinney code. Furthermore, new radial velocity data from EH Cnc presented in this study for the first time has produced absolute physical and geometric parameters for this A-subtype W UMa-type variable. Analysis of eclipse timing data confirms the presence of sinusoidal-like excursions in the eclipse timing residuals. We address whether these are due to magnetic activity cycles, the so-called “Applegate effect”, or related to a light-time effect (LiTE) resulting from the presence of a third gravitationally bound cool low mass white dwarf. A model using the PAdova & TRieste Stellar Evolution Code (PARSEC) has provided valuable insight about the evolutionary history of EH Cnc as a trinary system.

中文翻译：

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对可变过接触系统 EH Cancri 的综合研究

2010 年、2014 年和 2018 年期间，从 EH Cnc 在两个地点获得了精确的多色 CCD 衍生的光度数据，其中每个时期使用不同的仪器。这提供了一个独特的机会，可以在 Roche 对通过使用 Wilson-Devinney 代码进行差分校正优化的光曲线建模后研究参数不确定性。此外，本研究中首次提出的来自 EH Cnc 的新径向速度数据已经产生了这个 A 亚型 W UMa 型变量的绝对物理和几何参数。对日食时间数据的分析证实了日食时间残差中存在类似正弦曲线的偏移。我们解决这些是否是由于磁活动周期，即所谓的“Applegate 效应”，或与第三颗受引力束缚的冷低质量白矮星的存在导致的光时效应（LiTE）有关。使用 PAdova 和 Trieste Stellar Evolution Code (PARSEC) 的模型提供了关于 EH Cnc 作为三元系统的进化历史的宝贵见解。