TESS data from May to June 2026 support uniform apsidal motion in V1647 Sgr at eccentricity 0.412

We test the eclipse interval of V1647 Sgr in TESS Sector 104, from May to June 2026. Wolf et al. (2026) studied four earlier TESS visits. We measure 53 eclipse times from five public QLP light curves. Eleven times are from Sector 104. Separate linear clocks for primary and secondary times give an interval of 1.13806324 days in the new visit, with a scatter error of 3.26 seconds. A uniform apsidal model fitted to the four earlier intervals predicts 1.13814826 days at fixed eccentricity 0.412. The measured interval is 7.35 seconds shorter than the prediction. The combined conditional error is 10.59 seconds. The later interval thus agrees with the earlier trend under this model. The interval increased by 72.04 minutes from 2019 to 2026. We test the profile, baseline, sample integration, event selection, aperture, and data reduction. Two corrected QLP products leave too few accepted primary eclipses for a new-visit interval. Older TESS-SPOC corrected intervals differ by up to 70 seconds. The quoted errors assume fixed geometry and independent event noise. They are not full errors on the physical apsidal rate. This retrospective test reports new times and no significant departure from steady apsidal motion. The package includes the unchanged source data, code, provenance, figures, and repeat checks.

V1647 Sgr · eclipsing binary · apsidal motion · eclipse times · TESS · QLP · reproducible astronomy