Transit Timing Observations from Kepler: VI. Transit Timing Variation Candidates in the First Seventeen Months from Polynomial Models

TL;DR

This paper analyzes Kepler data to identify and characterize transit timing variation (TTV) candidates among 1481 planet candidates, finding a higher TTV occurrence rate in systems with multiple transiting planets, and providing a basis for future confirmation and study.

Contribution

It presents an updated TTV analysis of Kepler planet candidates, identifying new strong and weak TTV candidates using polynomial models, and highlights the increased TTV occurrence in multi-planet systems.

Findings

39 strong TTV candidates identified

136 weaker TTV candidates identified

TTV occurrence rate is ~68% higher in multi-planet systems

Abstract

Transit timing variations provide a powerful tool for confirming and characterizing transiting planets, as well as detecting non-transiting planets. We report the results an updated TTV analysis for 1481 planet candidates (Borucki et al. 2011; Batalha et al. 2012) based on transit times measured during the first sixteen months of Kepler observations. We present 39 strong TTV candidates based on long-term trends (2.8% of suitable data sets). We present another 136 weaker TTV candidates (9.8% of suitable data sets) based on excess scatter of TTV measurements about a linear ephemeris. We anticipate that several of these planet candidates could be confirmed and perhaps characterized with more detailed TTV analyses using publicly available Kepler observations. For many others, Kepler has observed a long-term TTV trend, but an extended Kepler mission will be required to characterize the system via TTVs. We find that the occurrence rate of planet candidates that show TTVs is significantly increased (~68%) for planet candidates transiting stars with multiple transiting planet candidate when compared to planet candidates transiting stars with a single transiting planet candidate.