AI 中文总结
本研究识别首个兼具额外互食的2+2型四合星TIC 433545934，结合TESS与地面数据经光动力学分析确定其参数，发现其外轨道偏心率高、系统高度共面，为已知第五致密的同类型系统。
AI 中文摘要
本研究识别并对TIC 433545934进行光动力学分析，它是首个同时存在外食的2+2型四合星双食系统。TESS发现了一次此类外食，引发了对该系统的特殊关注。本研究的大部分数据来自TESS观测，同时还获取了该四合星系统的补充地面测光测量数据。将从TESS及后续地面数据中提取的食时变曲线、测光光变曲线与光谱能量分布相结合，进行复杂的光动力学分析，以确定该具有动力学意义系统的恒星与轨道参数。两颗内部食双星的轨道周期分别为$P_A=2.07$天和$P_B=1.41$天，外轨道周期为$P_{AB}=224.5$天，仅外周期就使该系统成为已知第五致密的2+2型四合星。此外，TIC 433545934的独特之处在于，当双星B的成员星掩食双星A的两颗成员星时，TESS观测到了一次三峰的额外食事件，还在ASAS-SN和ATLAS的存档地面数据中识别到了类似的额外食事件。但这些额外事件仅在外轨道公转期间发生一次，即双星A不会掩食双星B的成员星，这与外轨道偏心率较高（$e_{AB}=0.62$）的发现一致。分析显示，双星A由两颗非常相似但略微演化的晚A型星组成（$q_A=0.92$），而双星B的主星质量介于双星A两颗恒星的质量之间，占主导地位（$q_B=0.60$），该系统高度共面，互倾角低于约2度。
英文摘要
In this work we identify and photodynamically analyze TIC 433545934, the very first doubly eclipsing 2+2-type quadruple stellar system, which shows outer eclipses, too. One such outer eclipse was discovered with TESS, which triggered a special interest in this system. Most of the data for this study come from TESS observations, but we also obtained supplemental ground-based photometric measurements for this quadruple system. The eclipse timing variation curves extracted from the TESS and ground-based follow-up data, the photometric light curves, and the spectral energy distribution are combined in a complex photodynamical analysis to yield the stellar and orbital parameters of this dynamically interesting system. The periods of the two inner, eclipsing binaries were found to be $P_A=2.07$d and $P_B=1.41$d, while the outer period is $P_{AB}=224.5$d. The outer period alone makes this system the fifth most compact known 2+2-type quadruple. Moreover, what really makes TIC 433545934 unique is that TESS observed a triple-dipped extra eclipsing event when the stars of binary B eclipsed the two components of binary A. We identified similar extra eclipsing events in the archival, ground-based data of ASAS-SN and ATLAS, as well. We found, however, that these extra events occur only once during an outer revolution, that is, binary A does not eclipse the stars of binary B. This is in accord with our finding that the outer eccentricity is quite high, being $e_{AB}=0.62$. Our analysis reveals that binary A consists of two quite similar, but slightly evolved late A-type stars ($q_A=0.92$), while in the case of binary B, the primary star, whose mass is between the masses of the two stars of binary A, is quite dominant, with $q_B=0.60$. The system was found to be substantially flat, with mutual inclination angles below $\approx2\degr$.
CommentsAccepted for publications in Astronomy and Astrophysics
