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 1.: KOI-841.03, Period: 6.55 days, no TTV observed.
Figure 2.: KOI-841.01, Period: 15.34 days; TTV present: P_ttv: 717.27 ± 19.83 days, well anti-correlated with the strongest P_ttv of KOI-841.02.
Figure 3.: KOI-841.02, Period: 31.33 days, strong TTV with P_ttv: 693.62 ± 28.61 days, well anti-correlated with that of 841.01.
Figure 4.: Sinusoidal array of 1st-order Residuals from Figure 3, implying the presence of a second TTV superimposed upon the first one (of Figure 3.), potentially due to an unseen, non-transiting planet ("841.06") in the "Lineweaver-Bovaird Rule"* orbital space (potentially near ~ 0.43 AU with a Period of ~ 103 days) between 841.02 and 841.04.
Figure 5.: Sinusoidal array of Residuals from Figure 4., i.e.: 2nd-order Residuals from Figure 3., potentially due to the TTV resulting from the mutual interaction of 841.02 and 841.04.
Figure 6.: Summed sinusoidal arrays of Figures 3., 4., and 5. showing the close agreement with the original data points of Figure 3.
Figure 7.: KOI-841.04, Period: 269.29 days, too few data points to clearly define a TTV. However, such is suggested by the relatively large amplitude (probably of the order of 50 minutes) of the few available (O-C)'s points.
[KOI-841.05 is currently listed in the NASA Exoplanet Archive as a False Positive.]