Top: part of O−C diagram of KOI-1452 between 1000 days ≤ BJD (+2 454 833) ≤ 1070 days. Middle: concurrent unsharp masking transit light curve residuals. The bright stripe is due to spot-crossing anomalies, which change their position from one transit to the next due to the small period difference (cf. Fig. 1). The white areas indicate no data. The black lines indicate the first and fourth contact of the eclipse. Bottom: variation of the measured radii R_B/R_A for each eclipse. During the strongest observed TTV the star appears to be larger because of spot coverage during the transit (Czesla et al. 2009).