A local calibration gives P1121 flux ratios of 0.983 in W1 and 0.965 in W2 for 2022–2024 relative to 2015–2017

We tested whether the mean infrared light of the young debris-disk star P1121 rose after its earlier quiet interval. We compared public NEOWISE measurements in 2022–2024 with 2015–2017. The target has 156 accepted paired exposures in 20 visits. A local correction uses 21 comparison stars, matched visits, and equal weights for the two scan seasons. The late/early geometric mean total catalog flux ratios are 0.9830 at 3.4 micrometers (W1) and 0.9649 at 4.6 micrometers (W2). Separate approximate 95 percent model ranges are 0.9643–1.0032 and 0.9402–0.9955. The model uses paired resampling and an extra target error from the field scatter. W1 allows no change. W2 suggests a small decrease, but extra assumed errors of 0.01 or 0.02 magnitude per visit allow no change in both bands. The tested models show no large mean rise. The controls are bluer than the target. Aperture checks have too few valid samples for an independent contrast. Thus, an intrinsic decrease is not secure, and short events between visits remain possible. We preserve the source responses, query receipts, code, figures, error draws, and a clean reproduction check.

P1121 · debris disks · NEOWISE · infrared variability · differential photometry · public data · reproducible research