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.
21 May 2015
Kepler KOI-456 (Kepler-160; KIC-7269974) 3-(or more?)-Planet System
Discussion: A sinusoidal curve-fit of the [(O-C) vs. Time] data for KOI-456.01 (Kepler-160c) showed (Figure below) a periodicity (P_ttv) of 872.73 ± 15.99 days; a Lomb-Scargle Periodogram (LSP) of the same data gave a high-credibility periodicity of 855.24 days. Potentially, a non-transiting planet is gravitationally interacting with KOI-456.01 in this stellar system other than KOI-456.02.