Fixed PRF fits in TESS sectors 73 and 79 place the TOI-5775.01 flux loss toward a nearby star

Which star produces the dimming assigned to TOI-5775.01? We fit public TESS pixel data in sectors 73 and 79 with fixed pixel response function (PRF) models. Six and eight covered events give mean flux-loss images. Both fitted positions are north of the assigned star, TIC 289666986. A nearby star, Gaia DR3 554418670902917248, is about 9.5 arcseconds north. Define alpha as the fitted displacement along the line from the target to this star, with zero at the target and one at the neighbor. We find alpha = 0.638 and 0.952 in the two sectors. Whole-event bootstrap samples give standard deviations of 0.169 and 0.127. The neighbor position gives smaller weighted residual sums than the target position in both sectors. Mask, background, and position-calibration tests retain the northward offset. These errors exclude PRF model error and uncertainty in the coordinate calibration. A fit to 41 event times in five sectors gives a period of 2.4364652 +/- 0.0000239 days. An improved working period was already in the public ground report. That report describes a dip on the assigned target, but its neighbor test does not clear the northern star. Simple fits to its 54 numerical measurements do not settle the conflict. The TESS image fits favor a nearby source under the tested model. They do not establish a final planet or binary classification. The package preserves code, input data, source hashes, event times, image fits, controls, and reproduction instructions.

TESS · TOI-5775.01 · TIC 289666986 · source position · pixel response function · blended stars · transit times · Gaia DR3 · exoplanet vetting · reproducible data