并非如此典型的双食系统
Not so typical doubly eclipsing systems
AI总结：
本研究发现5个仅一对恒星存在周期变化的特殊双食系统，其经典食时变化分析方法不适用，目前提出了若干起源假设但尚未得出决定性解释。
AI中文摘要：
经典双食系统是指那些被检测到来自一个点源的两个不同食周期的恒星系统。通过详尽分析，可以揭示这些系统中组成恒星的物理参数，有时甚至能约束两个双星围绕共同质心的相互运动。这通常是通过研究两对恒星的食时变化来实现的，由于两个双星围绕共同质心旋转，它们的食时变化行为应彼此相反。本研究中，我们呈现了这类简单方法无法适用的相当特殊的系统，其周期变化可明确检测，但仅存在于其中一对恒星。这些特殊系统包括：V736 And（周期0.3596天和0.3069天）、ASAS J074939-3037.0（0.4417天，0.2648天）、OGLE BLG-ECL-123507（1.0170天，2.9488天）、ASASSN-V J180818.54-684329.4（0.3392天，3.3234天）以及CRTS J191726.4-543540（0.3129天，2.8178天）。研究提出了关于此类行为可能起源的若干假设，但仍未得出最终决定性解释。
英文摘要：
Classical doubly eclipsing systems are stars for which two distinct eclipsing periods that apparently come from one point source are detected. Through thorough analysis, the physical parameters of the component stars of these systems can be revealed, and sometimes even the mutual motion of the two doubles around a common barycentre can be constrained. This is most typically done via study of the eclipse-timing variations for both pairs, whose behaviour should be opposite in manner to each other, as the two doubles revolve around a common barycentre. In this study, we present rather unusual systems for which such an easy approach does not work. The period changes are clearly detectable, but only for one pair. These unusual systems are V736 And (periods 0.3596 days and 0.3069 days); ASAS J074939-3037.0 (0.4417 d, 0.2648 d); OGLE BLG-ECL-123507 (1.0170 d, 2.9488 d); ASASSN-V J180818.54-684329.4 (0.3392 d, 3.3234 d); and CRTS J191726.4-543540 (0.3129 d, 2.8178 d). Several hypotheses are presented regarding the possible origins of such behaviour. However, a final decisive explanation is still yet to be determined.
