The secondary eclipse phase of AL Doradus decreases from 2018 to 2025 with symmetric profile fits

We test if later public TESS data show a decrease in the relative secondary eclipse time of AL Doradus. We fit symmetric profiles to 43 SPOC light curves with 120 second exposures. Fixed coverage rules give 117 accepted eclipses and 17 complete primary-secondary-primary sets in separate sectors from December 2018 to September 2025. A phase formed from each set removes a common affine change of its times. Its equivalent time decreases by 10.150 seconds per year. The 95% HC3 statistical interval is 9.750 to 10.550 seconds per year for the decrease, under independent sectors and a linear trend. Data from 2023–2025 alone also show a decrease. The tested SAP profile settings give slopes within 0.058 seconds per year. Independent uniform-disc eclipse simulations at the actual sample times have slope errors below 0.01 second per year. PDCSAP gives larger scatter and a less precise slope. Under fixed eccentricity and geometry, the main slope gives a total apsidal rate of 0.0001535 degrees per cycle. Flux processing and stellar surface effects limit this physical interpretation. This work extends a known apsidal timing record. It includes source hashes, lossless numerical columns, all event decisions, code, figures, and instructions for an offline reproduction.

AL Doradus · TESS · eclipsing binaries · apsidal motion · eclipse timing · public data · reproducible research