RZ Piscium W2 flux decreased between July 2022 and December 2023 under Gaussian errors and independent 0.02 mag visit floors

The final NEOWISE archive permits a test of the infrared decline reported for RZ Piscium through 2021. We reduce public paired W1 and W2 exposures with official scan corrections and twelve catalog-selected local comparison stars. The main rules retain 224 exposures in 20 visits from July 2014 to December 2023. A fixed test compares four visits in 2020–2021 with two visits in 2023. The W2 mean change is +0.0206 ± 0.0183 magnitudes. Its simultaneous 95% Gaussian interval is −0.0232 to +0.0643 magnitudes for three fixed contrasts. This test does not resolve a change between the sampled means. An added search tests all 190 visit pairs in W1, W2, and color. From July 2022 to December 2023, W2 changes by +0.2033 ± 0.0384 magnitudes. Its simultaneous interval for all 570 tests is +0.0525 to +0.3541 magnitudes. This is a flux decrease of 17.1%, with interval 4.72% to 27.8%. The model assumes Gaussian errors and an independent 0.02 magnitude floor per band and visit. Paired exposures and whole comparison series supply the bootstrap covariance. The event interval includes zero if the floor is 0.04 magnitudes. A stricter fit-quality cut leaves too few July 2022 exposures to test the event. July-only and December-only mean contrasts have opposite signs. No color pair excludes zero in the full search. The result constrains combined system flux; it does not identify a planet or a physical cause. The package supplies raw tables, exact queries, source hashes, all exposure decisions, full covariance, code, figures, and independent calculation checks. Earlier work already established infrared variability in this source.

RZ Piscium · NEOWISE · infrared variability · circumstellar dust · differential photometry · reproducible research