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Exoplanet-Science.com

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-244.02, P = 6.24 days [Plot avg. error bars = ± 1.48 min.]
TTV_minimum: 182.49 ± 12.57 days, Amp_ttv_minimum: -3.46 ± 0.52 min.
TTV_maximum: 344.81 ± 13.26 days, Amp_ttv_maximum: 4.03 ± 0.52 min.
TTV_minimum: 507.12 ± 14.30 days, Amp_ttv_minimum: -3.46 ± 0.52 min.
TTV_maximum: 669.44 ± 15.62 days, Amp_ttv_maximum: 4.03 ± 0.52 min.
TTV_minimum: 831.76 ± 17.16 days, Amp_ttv_minimum: -3.46 ± 0.52 min.
TTV_maximum: 994.07 ± 18.87 days, Amp_ttv_maximum: 4.03 ± 0.52 min.
TTV_minimum: 1156.39 ± 20.70 days, Amp_ttv_minimum: -3.46 ± 0.52 min.
TTV_maximum: 1318.71 ± 22.62 days, Amp_ttv_maximum: 4.03 ± 0.52 min.
TTV_minimum: 1481.03 ± 24.61 days, Amp_ttv_minimum: -3.46 ± 0.52 min.
P_ttv: 324.63 ± 4.67 days.
Amp_ttv: 7.48 ± 0.73 minutes.
Lomb-Scargle periodogram, periodicity (P_ttv): 324.37 days; Power: 28.59; FAP: 7.780 x 10^-10.
Linear ephemeris (this work): Tc = 6.23853378(Tc#) + 104.70663612

Figure 2.: KOI-244.01, P = 12.72 days [Plot avg. error bars = ± 0.59 min.]
TTV_maximum: 178.48 ± 16.22 days, Amp_ttv_maximum: 1.45 ± 0.27 min.
TTV_minimum: 341.48 ± 17.06 days, Amp_ttv_minimum: -1.67 ± 0.27 min.
TTV_maximum: 504.47 ± 18.34 days, Amp_ttv_maximum: 1.45 ± 0.27 min.
TTV_minimum: 667.46 ± 19.99 days, Amp_ttv_minimum: -1.67 ± 0.27 min.
TTV_maximum: 830.45 ± 21.91 days, Amp_ttv_maximum: 1.45 ± 0.27 min.
TTV_minimum: 993.44 ± 24.04 days, Amp_ttv_minimum: -1.67 ± 0.27 min.
TTV_maximum: 1156.44 ± 26.34 days, Amp_ttv_maximum: 1.45 ± 0.27 min.
TTV_minimum: 1319.43 ± 28.75 days, Amp_ttv_minimum: -1.67 ± 0.27 min.
TTV_maximum: 1482.42 ± 31.26 days, Amp_ttv_maximum: 1.45 ± 0.27 min.
P_ttv: 325.98 ± 5.92 days.
Amp_ttv: 3.11 ± 0.38 minutes.
Lomb-Scargle periodogram, periodicity (P_ttv): 326.51 days; Power: 17.21; FAP: 3.481 x 10^-5.
Linear ephemeris (this work): Tc = 12.72037462(Tc#) + 111.52824429

For literature references, including Tc#, Tc, and major TTV tabulations, see my "Summary" webpage.(TTVs for this particular system, for Q1-13, were reported by Xie,2013.)

16 Sep 2014
KOI-244 (Kepler-25, KIC-4349452) 2-Planet System

Mean motion resonance (MMR) between the two known planets in this system is suggested by their near-integer period ratio (P_244.01:P_244.02) of 2.039.  And their strong gravitational interaction is evidenced by their very closely anti-correlated TTVs (see following figures and data).