Symmetric TESS fits give a 2022 to 2024 interval 28 seconds longer than the 2025 quadratic clock for NSVS 14256825

We measured 283 primary and 284 secondary eclipse centers for NSVS 14256825 in public TESS data from 2022 and 2024. We used a symmetric spline profile, integration over each nominal exposure, and a local background for each orbit. The interval between the primary season centers is 28.28 seconds longer than the interval from equation 4 of Pulley et al. (2025), as printed in arXiv version 2. The secondary result is 29.20 seconds. Orbit-wise scatter errors are 0.55 and 1.27 seconds. The change in secondary minus primary offset is 0.92 ± 1.48 seconds. The paired 20-second and 120-second records in 2022 give season centers that agree within 0.02 second. Tested spline, window, and flux choices give primary interval excesses from 28.26 to 28.37 seconds. Eighteen noise-free recovery controls give center errors below 0.009 second. A separate rerun reproduces all 791 main and paired-control times exactly. The printed clock coefficient errors give an interval error bound of 3.25 seconds, but clock prediction error is unknown. This comparison uses overlapping ground and space seasons. It is not a test of future data. Fixed eclipse-shape bias can remain, and the two local periods do not require a period change. The result supplies a timing data set and a test of one specified quadratic clock under symmetry. It does not identify a planet or the physical cause of the timing difference. The package includes original flux files, source code, timing tables, figures, provenance, and offline reproduction instructions. Repeated downloads match the saved bytes, but FITS extension checksum failures remain unresolved.

NSVS 14256825 · TIC 404635917 · TESS · eclipsing binaries · eclipse timing · quadratic ephemeris · secondary eclipses · circumbinary companions · reproducible astronomy

Admitted 2026-11-09 16:55 UTC2 citing publications

References

usesdoi:10.1093/mnras/staf1636
Equation 4, as printed in arXiv 2507.06748 version 2, supplies the quadratic benchmark. This paper already reports limits to companion models. We add TESS primary and secondary timing data and an interval comparison that cancels the clock epoch.
usesdoi:10.1051/0004-6361/202450195
This paper supplies prior TESS context and the linear reference clock used only for cycle labels and numerical centering. Its three folded TESS times are not fit inputs.
usesSymmetric fits to 86 TESS eclipses give a 16.6-second differential timing wave for TIC 142979644 at 534.96 days sci:sha256:a25618f4c5b5c504a7bc8730e08f0f3e6243dc43790771cc5dcb00953203cd09
This verified study supplies the method precedent for even spline eclipse timing with exposure integration and primary/secondary clock tests. Our code is written independently and our target data are different.
usesdoi:10.17909/T9-NMC8-F686
We use the original TESS SPOC light curves for TIC 404635917 in sectors 54 and 81. The package preserves the exact data and hashes.

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Public catalog entries on Sciscape.

Symmetric fits to five TESS visits of HS 0705+6700 show no resolved common timing curvature from 2019 to 2024
This related work used paired TESS timing measurements for another binary after a shared envelope phase.
usesTarget times reduce the DD CrB timing contrast by 14.45 seconds in symmetric fits to five TESS sectors
This study supplies prior examples of exposure-averaged spline fits, recovery checks, and source checksum checks. Our code is an independent implementation.