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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.

Figure : KOI-7042.01, P = 13.25 days [Plot avg. error bars = ± 0.189 min.]
TTV_maximum: 350.71 ± 37.14 days, Amp_ttv_maximum: 0.158 ± 0.03 min.
TTV_minimum: 676.99 ± 43.43 days, Amp_ttv_minimum: -0.153 ± 0.03 min.
TTV_maximum: 1003.28 ± 52.09 days, Amp_ttv_maximum: 0.158 ± 0.03 min.
TTV_minimum: 1329.57 ± 62.15 days, Amp_ttv_minimum: -0.153 ± 0.03 min.
P_ttv: 652.58 ± 25.35 days.
Amp_ttv: 0.31 ± 0.05 minutes.
Lomb-Scargle periodogram, candidate P_ttv: 644.88 days; Power: 12.36; FAP: 0.00408.
Linear ephemeris (this work): Tc = [13.25413472 ± 0.00000047](Tc#) + [69.36845654 ± 0.00002846]


Numerous literature and major Tc#, Tc, and TTV tabulation references can be found on my "Summary" webpage following the table.

1 May 2015
                Kepler KOI-7042 (KIC-8445775) 2-(or more?)-Planet System

Discussion:
In the example of KOI-7042.01, a sinusoidal curve-fit of the (O-C) vs. Time data showed (Figure below) a periodicity (P_ttv) of 652.58 ± 25.35 days; 644.88 days was observed in the Lomb-Scargle Periodogram (LSP) of the same data.  Probably at least 2 planets (with only KOI-7042.01 transiting) are mutually-interacting to give the TTV distribution observed.
KOI-7042.01 appears to be a grazing planet since the ratio of T{FWHM}:tau for every transit is 1.0000 (characteristic of an isosceles triangle).  Furthermore, the relatively small amplitudes of the TTV (see below) could be consistent with the very large (4.485 Rp/R_jupiter) size & mass of this planet (assuming other similarly large ones are not those involved in the TTV-producing gravitational interactions).

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