WASP-79 b TESS times fit a constant period from 2018 to 2026 under independent timing errors

We tested whether the tentative period decrease of WASP-79 b continued in 2026. We measured 34 transits in six public TESS 120-second light curves from 2018, 2020, and 2026. Ten times are from new sectors 106 and 107. Fixed time-coverage rules selected events. We used exposure-integrated transit fits and residual block resampling. A constant period fits with chi-square 23.60 for 32 degrees of freedom. A quadratic clock gives +15.9 ± 17.5 milliseconds per year, with a conditional 95% interval from −18.3 to +50.2. The quadratic BIC is 2.70 higher than the linear BIC. These errors assume independent transits. An assumed 30-second offset shared by each sector increases the rate error to 50.0 milliseconds per year and includes the earlier central rate of −69. Quadratic baselines, SAP flux, and an early fitted transit shape also agree with a constant period. The 2026 times occur 201.9 ± 74.9 seconds later than a fit to the old published quadratic clock predicts, with its full coefficient covariance and excess scatter included. The data do not require a period change. A firm exclusion of the earlier tentative rate depends on shared errors. The package contains the original FITS files, hashes, 34 times, code, numerical results, figures, and offline reproduction steps.

WASP-79 b · TESS · transit timing · orbital period · orbital decay · correlated errors · reproducible analysis