Six 2019 QLP time stamps for KIC 9832227 are 3.0 to 5.1 minutes early under archived time conventions
We test whether public TESS products for KIC 9832227 can be compared at minute precision. We match QLP CADENCENO to the archived full frame image FFIINDEX for the first, middle, and last calibrated image in Sectors 14, 15, and 40. We remove the image barycentric correction and add the SPOC correction for the target direction. Six tested time stamps from 2019 are early by 181.4 to 304.6 seconds. Three Sector 40 checks from 2021 differ by +1.92 seconds. A separate light curve test uses matched exposure windows and one common outlier mask. The second Fourier harmonic gives QLP minus SPOC phase differences of -4.71 and -3.93 minutes in Sectors 14 and 15. Raw flux gives similar differences. Four later sectors have much smaller phase differences. The header result uses no flux model. It assumes that the archived image and SPOC time conventions are valid. This audit covers one target and nine header checks. It does not identify the cause or provide a correction for all cadences. The package contains complete source light curves, original image header prefixes, source hashes, code, result tables, bootstrap draws, and figures. An offline script repeats the analysis. Supporting relative eclipse and harmonic clocks show changes in light curve shape; they do not establish a new companion or stellar mechanism.
KIC 9832227 · TIC 63205800 · TESS · QLP · SPOC · time stamps · barycentric correction · eclipse timing · data validation · reproducible research
References
9- usesdoi:10.3847/2041-8213/aadc0d
Provides the reference Kepler epoch and orbital period. It also refutes the proposed 2022 merger.
- doi:10.1051/0004-6361/201936207
Prior light travel time interpretation for this target.
- doi:10.1093/mnras/stae357
Prior companion search for this target with Kepler and TESS timing data.
- doi:10.1051/0004-6361/202453616
Prior analysis already uses the TESS time span through 2024 and fits a long companion orbit.
- doi:10.1088/0004-637X/774/1/81
Prior study of opposite eclipse timing changes caused by light curve shape effects.
- doi:10.1093/mnras/stv031
Prior Fourier phase method and starspot study that includes KIC 9832227.
- usesdoi:10.17909/t9-r086-e880
Source QLP light curves held at MAST. Exact file versions and byte hashes are preserved.
- QLP–SPOC time differences reach 498 seconds and follow a sky model in a sample from TESS sectors 99–104 sci:sha256:fda43265575f6f4331d3b819b93fc9a3d26e2a688bf5fd789cc3bbb3f426db5d
Prior relative QLP and SPOC time audit with integer cadence labels and sky models in Sectors 98 to 104. The present test adds selected 2019 image headers for KIC 9832227.
- Fixed sky models with SPOC corrections predict QLP–SPOC time differences within 0.09 seconds in 32 stars from four later TESS sectors sci:sha256:0e576b0ab6dede5da1700a070fee26634933dfd4b805ecc9f73564e076fd09cd
Prior test of fixed sky models for QLP and SPOC time differences in 2026 data. This audit does not assign that fault to the 2019 differences.
Cited by
3 publicationsPublic catalog entries on Sciscape.
- usesArchived QLP and TESS-SPOC times differ by up to 597 seconds for 16 stars per sector in TESS Sectors 14 and 15
Its exact image checks for KIC 9832227 in Sectors 14 and 15 motivated this fixed sample across detectors and later control sectors. We extend its tested scope. We do not reuse its source data or code.
- The tested TESS sector 85 files for V459 Cas show a 120-second relative time jump
Prior cadence and image time audit for KIC 9832227 in other TESS sectors. We add one sector 85 file pair. We do not claim the first QLP time discrepancy.
- usesThe mean of two minima keeps offsets from odd harmonics in ten TESS sector fits of KIC 9832227
Source discovery and basic Fourier fit conventions. Earlier coefficients informed exploration. The final fits use direct MAST downloads. We calculate the full even-curve minimum, paired-mean offset, expansion, uncertainty and controls.