Eleven TESS sectors reject periods from 10 to 34 days for TOI-6666.01 if its measured event repeats at a depth of at least 600 ppm

TOI-6666.01 (TIC 256429408) has one known long event in TESS Sector 24. We test which constant orbital periods conflict with no repeat in eleven public SPOC two-minute light curves from 2019 to 2024. A local trapezoid fit gives a total duration of 16.883 hours and a corrected-flux depth of 1305 ppm. The dip is also present in aperture flux. We hold the measured shape fixed and test repeats with depths of 600, 789, 1000, and 1250 ppm in the delivered corrected flux. A repeat must cross five times a local noise floor and conflict with the observed depth by the same margin. This is an operational threshold, not a calibrated false alarm probability. All four depths give 37 usable windows with a total length of 148.24 days. No covered center outside the original event exceeds the threshold. The test rejects all periods from 10 to 34.0 days. Across 10 to 2000 days, it rejects 248 intervals with a total length of 346.42 days: 17.41% of period length, or 57.74% of log period length. These fractions are not orbital probabilities. The five early sectors alone reject 5.43% by period length and all periods from 10 to 26.5 days. The earlier estimate of 382 days remains open. Tests at the bootstrap duration limits retain the 34.0-day boundary. A duration increase of 20% reduces the continuous rejected range to 10 to 26.5 days. Fine-grid checks, explicit signal additions, and an independent interval test pass. The result assumes a fixed epoch and shape, constant timing, and retention of the signal in corrected flux. It does not confirm a planet. The package contains exact input files, hashes, source URLs, code, figures, interval tables, sensitivity tests, and reproduction instructions.

TESS · TOI-6666.01 · TIC 256429408 · single transit · orbital period · observing windows · transit search · signal injection · reproducible astronomy