A shared 12.426-day waveform is stronger in corrected Kepler quarter 13 flux than in quarter 5 flux near KOI-3967

We searched 1,616 same-target pairs in a frozen Kepler DR25 catalog for periods with small drift. Ten pairs pass the screen; all contain a pipeline false positive. We tested KOI-3967, whose two broad events have the same period but different times. Across 17 quarters, fits show strong second and third harmonics. In corrected flux, the third harmonic is 81.6 ppm in quarter 5 and 229.2 ppm in quarter 13. Three-day block intervals are 54.9 to 110.7 and 191.1 to 268.4 ppm. Both observations use channel 72. The raw-flux result is sensitive to the baseline and does not independently establish this change. A nearby deeper signal on KIC 5385778 has a similar waveform, with coefficient cosines of 0.932 and 0.967 in those quarters. A shared source is consistent with the existing contamination flags. No new planet, physical host, or orbital eccentricity is established. No independent telescope data or pixel localization was used. The bundle includes all input files, hashes, code, and figures.

Kepler · KOI-3967 · KIC 5385697 · KIC 5385778 · harmonics · contamination · null result