Under a linear transit clock, 20-second TESS data from 2021–2024 do not resolve a half-depth width change in WD 1856+534 b

We compare the transit half-depth width of WD 1856+534 b in public 20-second TESS data from 2021–2024. Coverage rules keep 267 events from 18 sectors. We fit a trapezoid after we average it over each exposure. Each date group has its own width and ingress duration. The model has a depth for each sector and a baseline for each event. The reported fit assumes a shared linear transit clock. The late width minus the early width is −15.0 seconds. The 95% interval is −36.2 to +10.2 seconds when we resample events within sectors. It is −34.2 to +9.0 seconds when we resample sectors within date groups. Both intervals include zero. The late ingress estimate is near its upper bound. About half of the resampled fits reach that bound. The original fit with separate event times gave different local solutions and sharp edges at a parameter bound. Artificial transits show the same problem in noisy cases. Thus the result is exploratory and depends on the clock, template, and bounds. It does not give a general bound on physical duration changes or additional planets. The package contains source hashes, a data extract, code, results, figures, and a successful clean reproduction check.

WD 1856+534 b · TESS · transit duration · white dwarf planets · public astronomical data · transit timing · block bootstrap · reproducible photometry