A free source model has lower minima near the bright neighbor of KIC 8164262 in TESS sectors 40 and 81

We test the source of the known 2.6184922 cycles per day signal of KIC 8164262 with public TESS pixel data. Sectors 40 and 81 contain 3917 and 11033 selected samples. A simultaneous fit at 19 catalog positions permits the bright neighbor, TIC 159649652, to vary at the same frequency. It gives target semi-amplitudes of 0.712 ± 0.158 and 0.614 ± 0.108 electrons per second. Errors use pixel-correlated scores in 0.5 day time blocks and condition on the spatial model. A second model fits one free response profile, the bright star, a background plane, and image gradients. Starts near the target give local minima 0.167 and 0.076 pixels from it. Searches across the full cutout find lower minima 0.633 and 0.729 pixels from the bright star. The weighted costs fall by 19.3% and 40.0%. Thus the local fits do not give a secure source identification. The catalog target component persists when bright central pixels are masked or bright-star shape terms are added. Structured residuals remain. The lower profiles must not be read as new stars or proof that the bright star causes the known signal. The contribution is a measured failure of local source attribution and a reproducible two-sector benchmark. The package includes original data, provenance, code, noise draws, cost surfaces, and figures.

KIC 8164262 · TESS · source localization · pixel response model · heartbeat binary · stellar oscillations · correlated noise · reproducible data