Two BD+05 4868 Ab transit cores show excess 10–12 μm local depression in JWST pipeline 3.0.0 spectra
We test local color in two consecutive transit cores of the known disintegrating planet BD+05 4868 Ab. We use all 48,850 calibrated spectra in public JWST program 8739, observation 1, with pipeline 3.0.0. We compare three phase windows with a log-flux contrast that cancels constant and linear trends. Relative to 8–10 μm, the 10–12 μm band has an extra local depression of 1,200 and 1,248 parts per million. Conditional standard deviations from residual blocks are 158 and 87 parts per million. The second value minus the first is 48 parts per million, with a conditional 95 percent interval from −310 to +403. Full-aperture cuts, wavelength subsets, and two-minute averaging retain positive contrasts. Restoring all recorded background variation reduces the values to 673 and 1,159 parts per million. Window shifts also change the amplitude. The analysis is exploratory. The contrast is not an absolute transit depth, and its noise model does not bound slow instrument changes. Prior MIRI work identifies detector effects in part of this wavelength range. These results establish a feature in the standard archive products; they do not identify its physical cause or a mineral. The package supplies minute spectra, exact source hashes, extraction records, code, figures, all stated checks, and reproduction instructions.
BD+05 4868 Ab · disintegrating planets · JWST · MIRI · public astronomical data · infrared spectroscopy · time series · background subtraction · reproducible research
References
3- usesdoi:10.3847/2041-8213/adbf21
We use the period and reference epoch for BD+05 4868 Ab. This prior work established the planet and variable optical dust transits.
- usesdoi:10.1051/0004-6361/202347127
This study describes MIRI response and persistence effects. It informs the limits on physical interpretation of our standard-extraction measurement.
- usesdoi:10.1038/s41550-024-02230-x
This study found long time changes in the 10.6–11.8 micrometre detector region in a different MIRI visit. It motivates the instrument-curvature caveat; it does not identify the cause in our visit.
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3 publicationsPublic catalog entries on Sciscape.
- usesA pixel mask fixed over one JWST visit retains positive infrared color contrasts in two BD+05 4868 Ab cores
We reuse its minute spectra as the pipeline reference. We also use its ephemeris, phase windows and conditional error convention.
- usesSeparate fixed backgrounds raise one control color contrast in an October 2025 BD+05 4868 Ab MIRI visit
This study supplies the selected target, phase windows, ephemeris, source product list, and pipeline minute spectra used for comparison.
- usesNine fixed image extractions give positive infrared color contrasts in two BD+05 4868 Ab cores
We reuse the verified minute spectra, wavelength grids, exposure start times, period, epoch, and phase windows. We add an extraction comparison from calibrated detector images.