论文标题
二进制行星的过境持续时间和时间变化
Transit Duration and Timing Variations from Binary Planets
论文作者
论文摘要
两个重力结合的系外行星的系统在其物理半径之外绕着一个常见的barycenter（“二进制行星”）绕着行星散射期间的潮汐捕获造成。由于动态潮汐，预计这些物体将在仅几次汇总半径中形成。由于它们的近距离近距离，它们的过渡重叠，导致一个具有较大有效尺寸的单个行星的欺骗性幻想，这种效果在存在嘈杂的数据和/或长时间整合时间的情况下加重了效果。我们表明，这些虚幻的单组分转运被称为“嵌合体转运”，对小时阶以及较小的过境时序变化（TTV）表现出较大的振幅转移持续时间变化（TDV）的影响。我们假设具有低冲击参数的二进制行星和具有恒星轨道的轨道的二进制行星，计算了过境持续时间上限的分析近似。我们使用Luna算法验证了表达式针对二进制木星的动态模拟的准确性，并为二进制行星系统中TDV信号的数值计算提供了Python代码（github.com/joheenc/binare-binary-binary-planet-transits）。此外，嵌合体从二元行星转移表现出可检测到的幅度和高频的TTV，落在最近确定的外显子走廊内。由于它们的异常形状，深度和持续时间，因此可以将这些物体标记为假阳性，但可以在现有档案中清楚地进行调查。
Systems of two gravitationally bound exoplanets orbiting a common barycenter outside their physical radii ("binary planets") may result from tidal capture during planet-planet scattering. These objects are expected to form in tight orbits of just a few times their summed radii due to dynamical tides. As a result of their close proximity, their transits overlap heavily, leading to the deceptive illusion of a single planet of larger effective size, an effect compounded in the presence of noisy data and/or long integration times. We show that these illusory single-component transits, dubbed "chimera transits", exhibit large-amplitude Transit Duration Variation (TDV) effects on the order of hours, as well as smaller Transit Timing Variations (TTVs). We compute an analytic approximation for the transit duration upper bound, assuming binary planets with low impact parameter and orbits coplanar with the stellarcentric orbit. We verify the accuracy of our expressions against dynamical simulations of binary Jupiters using the luna algorithm, and provide a Python code for numerical calculations of the TDV signal in binary planet systems (github.com/joheenc/binary-planet-transits). Additionally, chimera transits from binary planets exhibit TTVs of detectable amplitude and high frequency, falling within the recently identified exomoon corridor. Due to their anomalous shapes, depths, and durations, such objects may be flagged as false positives, but could be clearly surveyed for in existing archives.
