Under tested models, source regions for three TOI-3724.01 dips lie within 5 arcseconds of the target

TOI-3724.01 has three known TESS dips whose times do not fit one constant period in an earlier study. We measure the source position of each dip in sectors 19, 59, and 73. We fit each pixel with a time baseline and a fixed dip shape. We then fit the reference image and the lost light with calibrated TESS pixel response functions. Residual samples use shared time blocks of 30, 60, and 120 minutes. Each choice has 2000 samples per event. We also change the baseline, image model, and fit region. The fitted offsets from the target are 1.10, 1.28, and 0.63 arcseconds. Expanded screening radii about the target are 4.11, 4.90, and 3.54 arcseconds. These radii combine the largest 99th percentile residual radius with the largest tested model shift. They are conditional on the tested models and local noise assumptions. Eight other Gaia source positions, at 14.7 to 35.9 arcseconds, lie outside these regions. The target and its companion at 1.73 arcseconds remain possible sources. A separate calculation bounds the companion light travel time effect. For a bound companion of at most two solar masses and a true separation of at least 700 au, its light travel time second difference is below 0.082 seconds across two 366.3522-day intervals. This assumes a constant intrinsic clock, a fixed observer direction, and a host radial speed below 100 kilometers per second. This bound does not test changes to the planet orbit. We do not confirm a planet. The package contains observations, hashes, code, 2700 simulated source tests, result tables, figures, and reproduction steps.

TOI-3724.01 · TIC 143642240 · TESS · transit source position · difference images · pixel response function · Gaia DR3 · light travel time · unexplained transit times · false positive tests