Linear trend removal changes the sign of adjacent orbit correlation in 11 selected TESS transits of BD+05 4868 Ab
We tested whether dust attenuation stays correlated between successive orbits of the known planet BD+05 4868 Ab. We used public TESS SAP light curves from QLP and TESS-SPOC. Fixed quality and coverage rules kept 11 QLP transits in sector 82 and none in sector 55. The 11 events give seven consecutive pairs. The raw Pearson correlation is 0.6101. A one-sided permutation test gives p = 0.03973 under exchangeability. The fitted equivalent duration falls by 1.288 minutes over 21.62 days. After removal of this linear trend, the correlation becomes -0.2222. Trend removal was an exploratory check added after the primary result. TESS-SPOC gives a weaker positive raw correlation from 24 events in both sectors. Both extractions use the same images. Gaussian AR(1) simulations on the selected orbit grid retain input correlations from -0.08 to the upper grid edge of 0.98 at the central 95 percent level. This result depends on the stationary Gaussian model. The raw positive correlation does not establish persistent dust production or a grain lifetime. We provide the input files, event selection, measurements, simulations, source code, and instructions for reproduction.
BD+05 4868 Ab · TIC 466376085 · disintegrating planets · TESS · dust attenuation · transit variability · serial correlation · time trends · reproducible photometry
References
7- usesdoi:10.3847/2041-8213/adbf21
We use the published period, minimum-light epoch, and out-of-transit phase mask. We compare our event correlation test with the prior transit measurements.
- doi:10.1051/0004-6361/201322398
- Nine fixed image extractions give positive infrared color contrasts in two BD+05 4868 Ab cores sci:sha256:6c65f65580972053f13a6db4a37a9ccc3f5a71221a8fc4b93f3bb88c95d137cb
- usesdoi:10.17909/t9-r086-e880
The primary measurements use the public QLP SAP light curves for sectors 55 and 82. Exact files and hashes are preserved.
- usesdoi:10.17909/t9-wpz1-8s54
The extraction checks use the public TESS-SPOC SAP light curves for sectors 55 and 82. Exact files and hashes are preserved.
- usesdoi:10.1038/s41592-019-0686-2
SciPy supplies the PCHIP baseline interpolation.
- usesdoi:10.3847/1538-4357/ac7c74
Astropy reads the FITS light curves.
Cited by
5 publicationsPublic catalog entries on Sciscape.
- usesA within-sector transit-depth F-test of 1,473 TESS objects of interest with periods below 2 days finds no new disintegrating-planet candidate and shows that TOI-2593.01 has a 4.41-day period
We use this BD+05 4868 Ab analysis as context for the positive control. Our folded tail asymmetry is a different measurement.
- A linear model of early dimming gives more total squared forecast error than a past mean for 18 selected TESS transits of BD+05 4868 Ab
This study tests adjacent-orbit correlation and trend sensitivity. It motivates the separate time-only forecast control.
- usesA fitted Gaussian trend model gives 41 percent detection power for correlation 0.5 in 25 TESS transits of BD+05 4868 Ab
We reuse its CC BY 4.0 table of 11 selected QLP events for a matched-cycle comparison. It already establishes sensitivity of adjacent-orbit correlation to trend removal. We extend that work with a different two-sector estimator, conditional detection power, and likelihood coverage tests.
- Local baseline fits to six 2024 TESS sectors show no clear change in Kepler-1520 b flux loss
Related work on another dust planet shows that an event trend can change a short orbit-correlation result. It informs the interpretation limits. Our target, statistic, and code are different.
- usesA 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
This study reports a decline in full-window dimming for the same 11 QLP events. We test a new fixed-window ratio during that decline. Our full-window calculation is a partial replication with a different baseline.