Local fits with a circular orbit leave the 2026 eclipse depth change of LTT 9779 b unresolved in five TESS sectors

We test whether the optical eclipse depth of LTT 9779 b changed in 2026. We fit 127 eclipses in five public 120-second TESS sectors from 2018 to 2026. Each event has a separate quadratic baseline and a fixed eclipse shape for a circular orbit. We select events by time coverage. The 22 eclipses in Sector 106 give a depth of 47.7 parts per million (ppm). The 105 earlier eclipses give 85.6 ppm. The measured change is -37.9 ppm. Resampling single events gives a standard deviation of 39.4 ppm and a 95% percentile interval of -114.4 to +41.3 ppm. Three-event blocks give -109.2 to +31.4 ppm. The data do not show a clear change under this model. Flux, baseline, window, geometry, and timing controls give the same conclusion. In the tested empirical noise model, a real 50 ppm change has only about 29% detection probability at a two-sided 5% threshold. One 2026 sector cannot measure an error shared by that sector. The result does not establish stable clouds. The contribution adds a 2026 eclipse measurement and a common event data set with explicit sensitivity. We preserve the original light curves, source hashes, event selection records, code, results, figures, and instructions to repeat the analysis.

LTT 9779 b · TESS · secondary eclipse · optical light · atmospheric variability · time series · public data · sensitivity