Fixed symmetric fits to 30 TESS transits of HD 189733 b give 8 seconds of timing scatter in 2021–2024

We tested whether the historical timing excess of HD 189733 b also occurs in three later TESS visits. Fixed symmetric transit fits give 30 complete profile centers from sectors 41, 54, and 81 in 2021, 2022, and 2024. Their root mean square residual about one fitted period and reference time is 7.93 seconds. No timing outlier was removed. A conservative one-sided 95% upper limit on independent Gaussian extra scatter is 10.56 seconds. This limit counts all residual scatter as possible extra scatter. It assumes an additive timing response and independent Gaussian extra scatter plus Gaussian measurement error. Nine dependent analysis choices give limits from 7.77 to 11.30 seconds. Tests with 155 artificial transits show that photon-only timing errors are too small. Tests with 1800 known shifts recover a slope of 0.9958. The ten shared 2021 centers agree with the Ivshina–Winn table to 1.67 seconds RMS. The combined data do not support a persistent independent Gaussian component near the historical 70-second benchmark. They do not identify the cause of the historical excess, test all correlated signals, or exclude all companion planets. All six input light curves, source records, code, tables, figures, and reproduction instructions are preserved.

HD 189733 b · TESS · transit timing · stellar activity · timing scatter · reproducible astronomy