TESS sector 98 shows a December 2025 rise at the position of ASASSN-14ko

We measured a large rise in public TESS sector 98 images at the catalog position of ASASSN-14ko. A defined rise marker occurs at BJD TDB 2461036.545, near 2025 December 27. The tested extraction and fit methods give valid markers from BJD TDB 2461035.649 to 2461037.924. This method range is not a confidence interval. The reference aperture rate changes by 53.43 electron/s between the selected low and high windows. Image checks place the increase near the host position. The reduction recovers two historical TESS peaks within 0.20 day of their published values, with a truncated fit window for the first peak. The new maximum depends on the reduction and remains unresolved. The rise marker is later than a peak forecast from the printed central 2022 clock. These are different observables, so we make no statistical rejection of that model. TESS cannot separate the host nuclei or unresolved blends. The package contains six sectors of compact input images, light curves, code, source requests, hashes, controls, and figures. All input arrays and numerical outputs were reproduced exactly from the original source files.

ASASSN-14ko · TESS · repeating nuclear transient · optical variability · image subtraction · public astronomical data