Kepler quarters 1 to 17 give no mean half-phase eclipse for KIC 12557548 in five local-window tests

We test for a mean secondary eclipse at orbital phase 0.5 in 17 public Kepler release 25 light curves of the known dusty system KIC 12557548. A local linear baseline gives 1897 raw-flux event measurements. Their mean deficit is -9.7 parts per million (ppm), with a 10-orbit block standard error of 11.1 ppm. Corrected flux, two time halves, and five local-window choices include zero in their 95% block intervals. A 100-ppm box eclipse, averaged over each exposure and added to the archived flux, gives mean responses of 90.8 to 94.4 ppm by quarter and product. Outer phase checks have offsets of tens of ppm and can include primary-event structure in their baseline windows. Thus, this test gives no mean eclipse detection and no general physical upper limit. Earlier work already reported a secondary-eclipse limit. This study adds a defined release-25 check, phase controls, and reusable event data. No new object or independent telescope confirmation is claimed.

KIC 12557548 · Kepler-1520 · secondary eclipse · null result · local baseline · dust