Data are from Q1-Q16.  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:
Near Mean Motion Resonance integers in this system:P_1236.01/P_1236.02: 2.903, ~ 3/1; P_1236.03/P_1236.01: 1.522, ~ 3/2.Pronounced TTVs are found for 1236.01 and 1236.03.  There is no simple correlated nor anti-correlated relationship and the P_ttv values are quite different.  This could suggest various other system characteristics...like the presence of another unseen (non-transiting) planetary perturber, differing eccentricities, precessions of orbits, etc.

1st: KOI-1236.02, P = 12.31 days [Plot error bars (smaller than symbol) = ± 8.94 min.]
No clear TTV found.
Linear ephemeris (this work): Tc = 12.30959404(Tc#) + 70.68963191

2nd: KOI-1236.01, P = 35.73 days [Plot error bars (smaller than symbol) = ± 5.89 min.]
TTV_minimum: 113.77 ± 57.20 days, Amp_ttv_minimum: -57.45 ± 11.77 min.
TTV_maximum: 669.36 ± 71.22 days, Amp_ttv_maximum: 78.20 ± 11.77 min.
TTV_minimum: 1224.95 ± 97.09 days, Amp_ttv_minimum: -57.45 ± 11.77 min.
P_ttv: 1111.18 ± 71.48 days.
Amp_ttv: 135.65 ± 16.65 minutes.
Lomb-Scargle periodogram, candidate P_ttv: 1136.36 days; Power: 10.22; P-value: 8.14 x 10^-6.
Linear ephemeris (this work): Tc = 35.73407911(Tc#) + 84.14247200.

3rd: KOI-1236.03, P = 54.40 days [Plot error bars (smaller than symbol) = ± 8.31 min.]
TTV_maximum: 213.61 ± 58.15 days, Amp_ttv_maximum: 136.06 ± 48.26 min.
TTV_minimum: 554.37 ± 67.61 days, Amp_ttv_minimum: -193.72 ± 48.26 min.
TTV_maximum: 895.13 ± 82.56 days, Amp_ttv_maximum: 136.06 ± 48.26 min.
TTV_minimum: 1235.90 ± 100.58 days, Amp_ttv_minimum: -193.72 ± 48.26 min.
P_ttv: 681.52 ± 45.95 days.
Amp_ttv: 329.78 ± 68.25 minutes.
Lomb-Scargle periodogram, candidate P_ttv: 674.13 days; Power: 4.70; P-value: 0.0295.
Linear ephemeris (this work): Tc = 54.40538141(Tc#) + 81.84571992

References:
Planet Hunters notations: http://talk.planethunters.org/discussions/DPH101e799?object_id=APH51029770.
For Q1-Q6 TTV data of 1236.01 and 1236.02 (thru ~ 563 (BJD-2454900) days), see: Ford2012arXiv-1201.1892.

Updated 23 Aug 2013
KOI-1236 (Kepler-279, KIC-6677841) 3-Planets

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