Eight published mode groups at fixed frequencies leave a 609 ppm pulse term in HD 60435 TESS sector 87

We test a steady model for the known December 2024 pulse of HD 60435. The primary model uses eight published mode groups at 40 fixed frequencies. All 80 sine and cosine coefficients are free. We use public TESS sector 87 data. We project slow trends out of both the data and model. A term in the previously selected one-day interval has amplitude 609.4 parts per million. Its formal error scale is 34.6 parts per million. Error estimates that allow correlated noise are 39.2 to 48.4 parts per million. Both flux products and all listed frequency checks leave a large local term. A 2019 control has no large excess. Quiet-data block trials give much smaller terms. An exact bound shows that the primary steady family can place at most 21.25% of its sampled squared signal in this day. This bound is a model property, not a measurement of physical stellar energy. The result constrains interference within the tested fixed mode groups. It does not exclude unknown modes, other continuous frequency choices, or frequency drift. The package preserves original data, code, provenance, all checks, figures, and reproduction instructions.

HD 60435 · TIC 340006157 · TESS · stellar pulsation · mode interference · fixed frequencies · energy concentration · reproducible astronomy