Two frequency sums in KIC 3230227 decrease relative to its eclipse clock from Kepler to TESS under a three-signal model

We test whether two proposed daughter frequency sums in KIC 3230227 change relative to its eclipse clock. We measure 55 Kepler and 31 TESS eclipse times from 27 public light-curve files. We combine the new clock estimates with published mean phase rates and their full covariance for a model with three signals. The TESS minus Kepler changes in f1+f2-22 f_ecl and f2+f4-26 f_ecl are -9.17 and -8.42 times 10^-5 cycles per day. Their working standard errors are 1.64 and 0.83 times 10^-5 cycles per day. Allowing any covariance between mode and clock estimates, with the adopted marginal errors and independent missions, gives standard error bounds of 1.68 and 0.87 times 10^-5 cycles per day. Both changes remain negative in seven eclipse controls, seven published signal-model controls, and five tests that remove one TESS visit from both estimates. The two sums share f2 and are not independent detections. The result is conditional on the fitted signal model. It does not identify an intrinsic mode change or test the full parent-daughter phase relation. The earlier coupling model already allowed a nonzero mismatch. We preserve the 86 new event times, original FITS files, source records, code, figures, and reproduction instructions.

KIC 3230227 · eclipse times · tidal oscillations · nonlinear mode coupling · Kepler · TESS · frequency sums · reproducible data