TTVs are derived from Q1-Q17 Kepler data. x-axes: “Observed Tc” (Mid-Transit Time): EXOFAST’s best-fits from Normalized PDCSAP_FLUX Kepler light flux vs. time (BJD_tdb - 2454900) data. y-axes: “(O – C)”: difference between Observed Tc and the Calculated Tc from the graphically obtained linear ephemeris.
Numerous literature and major Tc#, Tc, and TTV tabulation references can be found on my "Summary" webpage following the table.
28 May 2015
Kepler KOI-1353 (Kepler-289; KIC-7303287) 3-(or more?)-Planet System
Discussion: A sinusoidal curve-fit of the [(O-C) vs. Time] data for KOI-1353.01 (Kepler-289c) showed (Figure below) a periodicity (P_ttv) of 1046.88 ± 61.82 days; a Lomb-Scargle Periodogram (LSP) of the same data gave a medium-credibility periodicity of 1047.11 days. Potentially, one other non-transiting planet is gravitationally interacting with KOI-xxx in this stellar system.