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Data are from Q1-Q15.  x-axes: “Observed Tc” (Mid-Transit Time): EXOFAST’s best-fits from Kepler light flux vs. time data.  y-axes: “(O – C)”: difference between Observed Tc and the Calculated Tc from the graphically obtained linear ephemeris.  The plots are pictured in the order of orbital periods (smallest first).

Discussion:

The TTV curves of 2672.02 and 2672.01 are very well anti-correlated and P_ttv values are quite similar (1324.41 and 1107.11, respectively) especially given the brevity of each sinusoidal curve.  The corresponding highly credible periodogram peaks (1465.20 and 1284.69, respectively) match well with the sinusoidal-curve results.  The ratio of the planetary periods is 2.059, i.e.: very close to a 2:1 ratio.

1st: KOI-2672.02, P = 42.99 days [Plot error bars (smaller than symbol) = ± 1.58 min.]
TTV_maximum:  171.32 ± 55.60 days, Amp_ttv_maximum:   21.72 ± 2.69 min.
TTV_minimum:   833.52 ± 76.44 days, Amp_ttv_minimum:   -29.62 ± 2.69 min.
TTV_maximum:  1495.73 ± 110.54 days, Amp_ttv_maximum: 21.72 ± 2.69 min.
P_ttv: 1324.41 ± 85.15 days.
Amp_ttv: 51.34 ± 3.80 minutes.
Lomb-Scargle periodogram, candidate P_ttv: 1465.20 days; Power: 12.69; P-value: 1.287 x 10^-11.
Linear ephemeris: Tc = 42.99264045(Tc#) + 95.49920926 [this work].
Estimated P_ttv = 1/|(nmmri_a/P_a - nmmri_b/P_b)| = 1506.86 days


2nd: KOI-2672.01, P = 88.51 days [Plot error bars (smaller than symbol) = ± 1.59 min.]
TTV_minimum:   341.38 ± 51.34 days, Amp_ttv_minimum:   -38.42 ± 6.03 min.
TTV_maximum:  894.94 ± 68.29 days, Amp_ttv_maximum:   60.84 ± 6.03 min.
TTV_minimum:  1448.49 ± 92.24 days, Amp_ttv_minimum:  -38.42 ± 6.03 min.
P_ttv: 1107.11 ± 60.27 days.
Amp_ttv: 99.26 ± 8.53 minutes.
Lomb-Scargle periodogram, candidate P_ttv: 1284.69 days; Power: 5.62; P-value: 0.000114.
Linear ephemeris: Tc = 88.51059487(Tc#) + 115.68429119 [this work].


References:
• P_ttv equation: P_ttv = 1/|(nmmri_a/P_a - nmmri_b/P_b)|…(see Fabrycky, et al., 2012, arXiv-1201.5415)
• Planet Hunters notations: http://talk.planethunters.org/discussions/DPH1011o6i?object_id=APH41080844&page=2&per_page=10.
• Other recent pertinent literature: Wang, et al., 2013, arxiv:1301.0644v1.

10 May 2013; updated 29 May 2013; updated 9 Aug 2013
KOI-2672 (Kepler-396, KIC-11253827) 2-Planets