A linear baseline gives tail to core dimming area ratios of 0.285 to 0.613 in 11 selected TESS sector 82 transits of BD+05 4868 Ab

We tested whether late-tail dimming falls relative to core dimming during a reported decline in total dimming for the known planet BD+05 4868 Ab. Fixed quality and coverage rules select 11 QLP transits in TESS sector 82. The sample spans 21.62 days. We integrate fractional dimming in core phase [-0.06, 0.06] and late-tail phase [0.10, 0.35]. Both windows use the same linear baseline from two quiet intervals. Tail area divided by core area ranges from 0.28485 to 0.61277. The mean is 0.43663. The fitted slope is -0.00521 per orbit. A two-sided test with 100000 permutations gives p = 0.356 under exchangeable event ratios. The conditional 95% slope interval is [-0.01736, 0.00694] per orbit under independent Gaussian event residuals. All ten fixed controls give no detected trend at the 0.05 level. They change the baseline, time reference, windows, or reduction. These tests do not prove a constant shape. An independent integration and artificial profiles verify the extraction. A hypothetical flux error confined to dimming intervals can change the weak fitted slope. The new contribution is a fixed-window ratio dataset and a time test that follow earlier work on variable transit shapes and total dimming. The package preserves four source light curves, hashes, selections, covariance arrays, figures, code, and reproduction instructions.

BD+05 4868 Ab · TIC 466376085 · TESS · disintegrating planet · transit shape · dust tails · equivalent duration · time trend · reproducible photometry