标题： 凌日折纸法：一种在时序光度测量中系统折叠外卫星凌日的方法 显示英文标题

标题： Transit Origami: A Method to Coherently Fold Exomoon Transits in Time Series Photometry

摘要： 识别一颗系外行星凌星的最简单方法之一是将光度时间序列数据围绕一个试验周期进行相位折叠——使用正确的值时可以得到相干叠加。 这种相位折叠的凌星已经成为现代凌星发现论文中的标准数据可视化手段。 对于系外卫星而言，没有类似的折叠机制，这需要某种形式的双重折叠；一次是针对行星，另一次则是针对卫星。 仅用行星项进行折叠时，卫星会在周围的凌外平均强度中引起一个小幅度的下降，但由于其非相干性，这远不如系外行星猎人熟悉的清晰叠加那么令人信服。 这里介绍了一种新方法，可以在行星表现出TTVs（凌星时间变异）的情况下实现所需的凌星折纸以双重折叠系外卫星。 这种双重折叠只有一个未知参数，即卫星与行星的质量比，因此可以使用简单的单维网格搜索快速识别与候选系外卫星相关的功率。 该技术在模拟光曲线中进行了演示，探索了近距离和/或倾斜卫星的极限情况。 作为示例，该方法被应用于Kepler-973b，这是一颗温热的小海王星，表现出8分钟的TTV，通过这种方法排除了由单一系外卫星引起的TTV的可能性，并且上限探查到了类似伽利略卫星大小的卫星。 显示英文摘要

摘要： One of the simplest ways to identify an exoplanetary transit is to phase fold a photometric time series upon a trial period - leading to a coherent stack when using the correct value. Such phase-folded transits have become a standard data visualisation in modern transit discovery papers. There is no analogous folding mechanism for exomoons, which would have to represent some kind of double-fold; once for the planet and then another for the moon. Folding with the planet term only, a moon imparts a small decrease in the surrounding out-of-transit averaged intensity, but its incoherent nature makes it far less convincing than the crisp stacks familiar to exoplanet hunters. Here, a new approach is introduced that can be used to achieve the transit origami needed to double fold an exomoon, in the case where a planet exhibits TTVs. This double fold has just one unknown parameter, the satellite-to-planet mass ratio, and thus a simple one-dimensional grid search can be used to rapidly identify power associated with candidate exomoons. The technique is demonstrated on simulated light curves, exploring the breakdown limits of close-in and/or inclined satellites. As an example, the method is deployed on Kepler-973b, a warm mini-Neptune exhibiting an 8 minute TTV, where the possibility that the TTVs are caused by a single exomoon is broadly excluded, with upper limits probing down to a Ganymede-sized moon.