Constant-clock controls give negative curvature in 700-node Kepler timing fits of KIC 3230227

We test a quadratic change in eclipse times of KIC 3230227 with public Kepler release 25 data. We use two flux products, three template resolutions, two local windows, and two baseline orders. In the narrow linear-baseline test, 700-node templates give curvature coefficients of -9.19 seconds in aperture flux and -11.02 seconds in corrected flux. With 1400 nodes, these become -2.52 and -3.70 seconds. Both 1400-node quarter-resampling intervals include zero. Constant-clock controls give -4.18 and -9.09 seconds with 700 nodes, and zero at the exact generating resolution. The added 120-second curves have biased recovery. These tests do not establish an orbital period change or a third body. One telescope, fixed mode frequencies, the template model, and data gaps limit the result. Code, data columns, exact source hashes, timing tables, controls, and figures are included.

Kepler · eclipse timing · binary stars · template error · null result