One ratio of transit losses fits eight TESS sectors of TOI-1266 under a local noise model

We tested whether the relative transit signals of TOI-1266 b and c changed between three TESS mission periods from 2019 to 2024. We used nine public 120-second SPOC light curves. We measured the integrated flux loss in a fixed three-hour window with a local linear baseline. Thirty transit windows passed fixed coverage rules. Eight sectors had signals from both planets. We fitted one common amplitude per sector and compared one c/b loss ratio with three mission ratios. Under a local noise model with independent transit errors, the common ratio is 0.517. Its conditional 95% profile interval is 0.432 to 0.607. The improvement from three ratios is 2.091, with a Gaussian simulation probability of 0.353. A control-noise simulation gives 0.350. The stated changes to flux product, baseline, window, and error scale give probabilities from 0.195 to 0.512. These data do not require a mission change in the loss ratio. This test has limited power. Under the fitted Gaussian model, it detects a 40% ratio increase in both extended missions in 46% of trials. The result does not establish constant peak depth or radius. The contribution contains derived loss measurements, a relative signal test, and an audit tool. The package preserves the nine source FITS files, input hashes, code, timing inputs, numerical results, simulations, and four figures. It uses the same observing sectors as prior work and adds no new planet or independent observations.

TOI-1266 · TESS · transit variability · integrated transit loss · flux dilution · reproducible analysis