Kepler KOI-1772 (KIC-3345675) 2-(or more?)-Planet System
Discussion: A sinusoidal curve-fit of the [(O-C) vs. Time] data for KOI-1772.01 showed (Figure below) a periodicity (P_ttv) of 1337.38 ± 229.81 days; a Lomb-Scargle Periodogram (LSP) of the same data gave a medium-credibility periodicity of 1613.98 days. Potentially, one other non-transiting planet is gravitationally interacting with KOI-1772.01 in this stellar system. The just ~ 1 sinusoidal cycle variation observed during Kepler’s “precision-lifetime” is responsible for the sizeable differences found for the P_ttv determined by the above-mentioned two methods.
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.