Accounting for Transit Timing Detectability: Biases in Planetary Radius and Orbital Period

Abstract Transit Timing Variations (TTVs) are deviations from the time an observer would expect to see an exoplanet transit its host star. In multiplanetary systems, significant TTVs may indicate the presence of another body in the system gravitationally interacting with the transiting exoplanet. T. Holczer et al. catalog 2599 Kepler Objects of Interest (KOIs) and provide a statistical analysis of their TTVs for candidates that have transited at least seven times. However, this conservative limit on the number of transits neglects long-period KOIs. Therefore, we extend the statistical analysis performed by T. Holczer et al. to the population of KOIs that have between three and six transits. We identify six KOIs, three of which have Kepler names (Kepler–103 c, Kepler–90 g, and Kepler–1662 c), with significant TTV signals that were originally overlooked by T. Holczer et al. Additionally, we search for trends regarding the planetary radius and orbital period of KOIs with significant TTVs. Through a survival analysis, we determine that planets with shorter orbital periods require larger TTV signals to be detected compared to longer period planets, regardless of planetary size. Uncovering trends in TTV statistics such as this one will provide targets for future forward modeling of planetary architectures.