Omitting Sector 67 reverses the fitted period change of LHS 3844 b with a fixed transit shape in eleven TESS sectors

We tested the transit clock of LHS 3844 b with eleven public 120-second TESS SPOC light curves from 2018 to 2026. Coverage cuts retain 502 events over 2879 days. Each event has a fitted baseline and depth. Each sector has a common center. With a fixed transit shape and four-event block bootstrap errors, a quadratic clock gives an apparent period change of -4.39 milliseconds per Julian year. The conditional 95% interval is -7.56 to -1.07 milliseconds per year. The quadratic fit has chi-squared 25.06 for eight degrees of freedom and a conditional goodness tail of 0.0081. Omitting Sector 67 changes the rate to +3.03, with an interval of -1.50 to +7.65. Omitting any other single sector keeps the point estimate negative. A separate fitted duration for each sector also gives an interval that includes zero. A 20-second fit to the same Sector 67 events differs from the 120-second center by only -0.30 seconds. The cadence products share photons. These tests do not establish orbital decay or explain the timing scatter. The contribution provides sector timing profiles, bootstrap draws, model controls, original input data, source records, code, and numerical checks. The main fit retains all accepted events and all eleven sectors.

LHS 3844 b · TESS · transit timing · orbital period · orbital decay · bootstrap · public astronomical data · reproducible research