The 7.59-hour KELT-9 signal is present in six TESS visits from 2019 to 2024

We tested the known KELT-9 pulse in six public TESS visits from 2019 to 2024. All six 120-second SPOC products returned for TIC 16740101 enter the study. We fitted slow trends, orbital harmonics, and sinusoids together outside primary and secondary eclipses. The visits span 1875.59 days. Local semi-amplitudes range from 99 to 123 parts per million (ppm). One common sinusoid gives a period of 7.586883 hours and a semi-amplitude of 111.5 ppm. One-day time blocks give standard errors of 0.000021 hours and 4.0 ppm. These errors assume one sinusoid and the selected count of cycles between visits. Simple aperture flux shifts the period by -0.147 seconds. Separate visit amplitudes and phases give no clear mismatch with the common model. A stronger, added test allows separate visit frequencies. It gives noise-test probabilities of 0.005 with one-day blocks and 0.024 with two-day blocks. These tests assume independent, symmetric residual blocks. They give evidence for small structure beyond one steady sinusoid, but do not identify its cause. The study measures the known signal in four later visits. It does not establish a new planet, an extra stellar mode, or a secular period change. The package preserves source FITS data, provenance, code, numerical results, simulations, figures, and offline reproduction instructions.

KELT-9 · TESS · stellar pulsation · frequency stability · time series · public data · reproducible photometry