ZTF DR24 records dimming in both g and r at ZTF J0923+4236 in February and May 2025

We use public ZTF DR24 data to extend the light curve of the known variable white dwarf ZTF J092311.41+423634.16 through 2025-10-20. We subtract a local offset from each exposure with six comparison stars per band. On 2025-02-23 and 2025-05-16, the target is 0.36–0.48 mag fainter than the early sampled bright level in both g and r. A fixed Pan-STARRS colour check retains these events. The band measurements are 26–113 minutes apart, so they do not measure simultaneous colour. We also compare observed nights in 2018–2023 with 2024–2025. The mean changes are −0.0132 mag in g and −0.0236 mag in r. Conditional 30-day block resampling gives 95% ranges of −0.0707 to +0.0449 mag and −0.0758 to +0.0269 mag. The fixed dimming threshold is the early 10th percentile plus 0.3 mag. The measured counts are 45/386 early and 6/94 late nights in g, and 56/446 early and 7/109 late nights in r. Ranges for both fraction changes include zero. Thus, the data record continued dimming in 2025 but do not resolve a change in sampled mean light or deep-night fraction. Unequal coverage and fixed calibration choices limit the comparison. The event check was chosen after target inspection. This extends the ZTF record in a 2024 study; variability was already known. The package preserves public responses, provenance, new code, an independent arithmetic check, figures, and an offline reproduction check.

ZTF J0923+4236 · white dwarfs · planetary debris · ZTF DR24 · differential photometry · stellar variability · public data · reproducible research