RZ Hor (TIC 31653503) is a long-period (P = 6.68 d) EA-type eclipsing binary that exhibits both chromospheric activity and oscillation. The physical properties of RZ Hor are determined with binary modelling for the first time. It is found that it has a semi-detached configuration with a low mass ratio of q = 0.1606(13), where the secondary component is filled with its Roche lobe. By analyzing all available eclipse times, it is shown that the orbital period of RZ Hor is decreasing at a rate of dP/dt = −5.48 × 10−6 d yr−1. In a typical Algol, a rapid mass transfer from the secondary to the primary should cause the orbital period to be increasing and then the secondary will be temporarily detached from the critical Roche lobe. The present configuration reveals that RZ Hor has undergone a rapid mass transfer and the period decrease can be explained by magnetic stellar wind. We estimate the rate of mass loss initially to be $10^{-8}\, M_{\odot }\, \mathrm{yr}^{-1} < \vert \dot{M}\vert < 10^{-6}\, M_{\odot }$ yr−1. The variations and the asymmetries of the light curve are interpreted by adding a migrating cool spot on the surface of the late-type secondary. After subtracting the eclipsing changes from the light curve data, we analyzed the pulsation in the light residuals. Twenty-five frequencies of signal-to-noise amplitude ratio (S/N) larger than 5.2, including four multiples of tidally split frequencies, were detected. A total of 17 independent frequencies containing 2 radial modes, and 10 non-radial p modes were identified. All the investigations suggest that RZ Hor is an evolved Algol-type binary with a δ Sct-type primary and an active secondary.

中文翻译：

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RZ Horologii 的光度分析：具有 δ Scuti 组件的进化和活跃的 Algol

RZ Hor (TIC 31653503) 是一个长周期 (P = 6.68 d) EA 型食双星，同时表现出色球活动和振荡。RZ Hor 的物理性质首次通过二元建模确定。发现它具有低质量比 q = 0.1606(13) 的半分离配置，其中次要组件充满了其 Roche 叶。通过分析所有可用的日食时间，表明 RZ Hor 的轨道周期正在以 dP/dt = −5.48 × 10−6 d yr−1 的速率减小。在典型的 Algol 中，从次级到初级的快速质量转移应该会导致轨道周期增加，然后次级将暂时脱离临界 Roche 瓣。目前的配置表明 RZ Hor 经历了快速的质量转移，周期的减少可以用磁星风来解释。我们估计最初的质量损失率为 $10^{-8}\, M_{\odot }\, \mathrm{yr}^{-1} <; \vert \dot{M}\vert <; 10^{-6}\, M_{\odot}$ yr−1。光变曲线的变化和不对称性是通过在晚型次生星表面添加一个迁移的冷点来解释的。从光变曲线数据中减去日食变化后，我们分析了光残差中的脉动。检测到信噪比 (S/N) 大于 5.2 的 25 个频率，包括潮汐分裂频率的四个倍数。总共识别出包含 2 个径向模式和 10 个非径向 p 模式的 17 个独立频率。