TESS 120-second data show a 50–53 ppm peak near 1.201 mHz in HD 217522 in 2026

HD 217522 is a magnetic Ap star with known changes in its pulsation spectrum. We measure its two known frequency bands in seven public TESS 120-second light curves from 2018 to 2026. In sectors 105 and 106, the largest corrected-flux peak in 1190–1230 microhertz is 50.42 and 52.65 parts per million at 1200.65 and 1200.60 microhertz. In sector 1, the largest peak was 31.61 parts per million at 1205.75 microhertz. The 2026 band power is below the 2018 value in this reduction. Thus, the larger peak does not show an increase in power across the whole band. Aperture flux and changes in trend removal retain the peak contrast. Tests with known sine waves recover peak amplitudes to within 0.6%, but recover only 91.1–99.2% of band variance. For sector 106, native 120-second flux and 20-second flux averaged to the same 11,408 times give peak heights that differ by 1.34%. Their band variances differ by 12.73%. No peak in 1990–2040 microhertz exceeds four times the local mean noise amplitude. This is a descriptive threshold, not a false-alarm probability. The contribution is a reproducible set of later measurements and checks. It does not establish changes in mode identity, total oscillation energy, or the cause of the variability. The package contains all eight source files, hashes, provenance, code, tables, spectra, and figures.

HD 217522 · TIC 139191168 · BP Gru · TESS · roAp stars · stellar pulsation · time series · public data