Five-slot fits of 1–3 h dips at a 1.1066 d period are below 0.5% in seven later TESS sectors of TIC 234284556 with quartic backgrounds

We test short states of repeating dips that a whole-sector fit can dilute. The data are from TIC 234284556 in seven public TESS sectors from 2023, 2025, and 2026. An earlier SCI study tested constant depth and phase for a whole sector. We instead scan five consecutive rotation slots at a fixed 1.1066 d period. Each fit needs at least three covered events. We test nine exposure-mean triangle profiles, with durations of 1–3 h, at 800 phases. Each event has its own quartic background. No primary fit reaches the declared 0.5% coefficient cut. The sector maxima range from 0.334% to 0.396% of median flux. The two historical dip sectors pass the search. We also add separate five-event signals with 0.75% depth between search phases. The search recovers 12,797 of 12,931 covered insertions (98.96%). There are 134 failed covered trials and 2,945 uncovered trials. The result concerns the stated profiles, period, archived flux, and fixed flare mask. It is not a physical depth confidence bound. Source files, provenance, code, grids, checks, and figures support reproduction.

TIC 234284556 · TESS · transient dips · stellar rotation · signal insertion · local polynomial fits