One line fits the two-band fluxes of WD 0145+234 in ten 2020–2024 NEOWISE visits under the tested error model

We test the variable two-band spectrum of WD 0145+234 in ten NEOWISE visits. These visits cover January 2020 through July 2024. A line in W1 and W2 flux space represents a fixed two-band spectrum plus arbitrary constant emission. Each visit has a free brightness. The fit includes errors in both bands and joint calibration covariance from 30 comparison sources. It gives Q = 5.72 for eight nominal residual degrees of freedom. Gaussian simulations with fixed covariance give p = 0.678. The variable W2/W1 flux ratio is 0.962. Its conservative 95% set is 0.768–1.187 under the stated errors. Removing the first 2020 visit widens this set to 0.092–3.224. Adding the three 2018–2019 high-state visits gives Q = 65.97 and rejects one line under the same assumptions. Tests with estimated exposure correlations and alternate calibration choices retain the primary fit. An assumed target band-error correlation of 0.9 causes rejection. Injected 5% W2 shifts in the final three visits are detected in only about 9% of trials. These data do not require spectral evolution in 2020–2024, but they do not establish constant dust temperature. The result is compatible with the published JWST spectral change. The package preserves raw inputs, signed source provenance, code, covariance matrices, simulation scores, figures, and reproduction instructions.

WD 0145+234 · white dwarfs · planetary debris · infrared variability · NEOWISE · two-band spectrum · errors in both variables · calibration covariance · reproducible astronomy