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TTVs are derived from Q0-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 1: KOI-92.01, P = 65.70 days [Plot avg. error bars = ± 1.95 min.]
TTV_maximum: 122.40 ± 46.60 days, Amp_ttv_maximum: 3.48 ± 1.56 min.
TTV_minimum: 338.64 ± 49.68 days, Amp_ttv_minimum: -4.45 ± 1.56 min.
TTV_maximum: 554.89 ± 55.17 days, Amp_ttv_maximum: 3.48 ± 1.56 min.
TTV_minimum: 771.13 ± 62.44 days, Amp_ttv_minimum: -4.45 ± 1.56 min.
TTV_maximum: 987.37 ± 70.93 days, Amp_ttv_maximum: 3.48 ± 1.56 min.
TTV_minimum: 1203.61 ± 80.27 days, Amp_ttv_minimum: -4.45 ± 1.56 min.
TTV_maximum: 1419.85 ± 90.18 days, Amp_ttv_maximum: 3.48 ± 1.56 min.
P_ttv: 432.48 ± 23.61 days.
Amp_ttv: 7.93 ± 2.20 minutes.
Lomb-Scargle periodogram, periodicity (P_ttv): 436.46 days; Power: 3.53; FAP: 0.187.
Linear ephemeris (this work): Tc = [65.70451995 ± 0.00015259](Tc#) + [70.44514000 ± 0.00193436]


Figure 2: Residuals of Figure 1 [Plot avg. error bars = ± 2.50 min.]

TTV_minimum: 297.14 ± 54.49 days, Amp_ttv_minimum: -3.68 ± 1.24 min.
TTV_maximum: 622.72 ± 63.26 days, Amp_ttv_maximum: 3.31 ± 1.24 min.
TTV_minimum: 948.30 ± 75.94 days, Amp_ttv_minimum: -3.68 ± 1.24 min.
TTV_maximum: 1273.88 ± 90.90 days, Amp_ttv_maximum: 3.31 ± 1.24 min.
P_ttv: 651.16 ± 38.24 days.
Amp_ttv: 7.00 ± 1.76 minutes.
Lomb-Scargle periodogram, periodicity (P_ttv): 655.23 days; Power: 3.90; FAP: 0.102.


Figure 3: Residuals of Figure 2; Residuals of Residuals of Figure 1 [Plot avg. error bars = ± 2.79 min.]

TTV_minimum: 132.77 ± xxx days, Amp_ttv_minimum: -2.48 ± 0.90 min.
TTV_maximum: 227.75 ± xxx days, Amp_ttv_maximum: 2.13 ± 0.90 min.
TTV_minimum: 322.74 ± xxx days, Amp_ttv_minimum: -2.48 ± 0.90 min.
TTV_maximum: 417.73 ± xxx days, Amp_ttv_maximum: 2.13 ± 0.90 min.
TTV_minimum: 512.72 ± xxx days, Amp_ttv_minimum: -2.48 ± 0.90 min.
TTV_maximum: 607.70 ± xxx days, Amp_ttv_maximum: 2.13 ± 0.90 min.
TTV_minimum: 702.69 ± xxx days, Amp_ttv_minimum: -2.48 ± 0.90 min.
TTV_maximum: 797.68 ± xxx days, Amp_ttv_maximum: 2.13 ± 0.90 min.
TTV_minimum: 892.66 ± xxx days, Amp_ttv_minimum: -2.48 ± 0.90 min.
TTV_maximum: 987.65 ± xxx days, Amp_ttv_maximum: 2.13 ± 0.90 min.
TTV_minimum: 1082.64 ± xxx days, Amp_ttv_minimum: -2.48 ± 0.90 min.
TTV_maximum: 1177.62 ± xxx days, Amp_ttv_maximum: 2.13 ± 0.90 min.
TTV_minimum: 1272.61 ± xxx days, Amp_ttv_minimum: -2.48 ± 0.90 min.
TTV_maximum: 1367.60 ± xxx days, Amp_ttv_maximum: 2.13 ± 0.90 min.
P_ttv: 189.97 ± 4.39 days.
Amp_ttv: 4.61 ± 1.27 minutes.
Lomb-Scargle periodogram, periodicity (P_ttv): 189.45 days; Power: 3.58; FAP: 0.175.


Figure 4.: Summed combination of Figures 1., 2., and 3. [Plot error bars = ± 4.22 min.]


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

1 Feb 2015
                Kepler KOI-92.01 (KIC-7941200) 4-(or more?)-Planet System

Discussion:
After a sinusoidal curve-fit of the (O-C) vs. Time data showed (Figure 1.) a periodicity (P_ttv) of 432.48 ± 23.61 days (436.46 days was observed in the Lomb-Scargle Periodogram (LSP) of the same data), a plot (Figure 2.) of the Residuals also gave a good sinusoidal curve-fit with a periodicity of 651.16 ± 38.24 days (LSP: 655.23 days).  Similarly, a plot (Figure 3.) of the Residuals of the Residuals gave a good sinusoidal curve-fit with a periodicity of 189.97 ± 4.39 days (LSP: 189.45 days).  The added combination of these three sinusoidal curves is arrayed in Figure 4. and reasonably reproduces a complex overall curvature consistent with the initial data.  While the sinusoidal behaviors observed could be partially due to orbital eccentricities, it is also possible that 3 additional as yet unseen (non-transiting) planets are present in the system.