QLP–SPOC time differences reach 498 seconds and follow a sky model in a sample from TESS sectors 99–104
Time errors can change the apparent times of planet transits. We measure QLP minus SPOC time in a fixed sample of 112 stars. The sample has 16 stars per sector in TESS sectors 98–104. Sector 98 is the control. The QLP team already reported a time correction fault in sectors 99–104. This study measures its size in the sampled files and tests a shared model. Integer cadence labels pair 200-second QLP exposures with nominally aligned 120-second SPOC exposures. No stellar brightness is used. There are 466,719 finite matched pairs. In sectors 99–104, measured differences range from −497.964 to +289.008 seconds. At each common cadence, three sky terms fitted to eight stars predict eight other stars. The test root mean square error is 0.230–0.349 seconds across these six sectors. An added constant term reduces it to 0.018–0.029 seconds. All 168,904 test residuals from the latter model are below 0.050 seconds in absolute value. Zero quality flags do not remove the large differences in sectors 100–104. The control differences remain near two seconds and span 0.069 seconds. These results test transfer across stars at shared times in fixed fields. They do not measure absolute clock accuracy or test new times. The package preserves native column extracts, full source headers, source hashes, query records, code, figures, and offline checks.
TESS · QLP · SPOC · time correction · transit timing · public data · calibration
References
2- usesdoi:10.17909/t9-r086-e880
This study uses native time, cadence, quality, and orbit columns from the QLP data products at MAST.
- doi:10.1117/12.2233418
This paper describes the SPOC pipeline used for the reference time columns.
Cited by
9 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
We use its general method of exposure labels and a model based on sky direction, with separate fit stars and test stars. We apply the method to Sectors 14 through 26. We do not reuse its source code or numerical data.
- usesFixed sky models with SPOC corrections predict QLP–SPOC time differences within 0.09 seconds in 32 stars from four later TESS sectors
We reuse all 112 selected stars, 224 native extracts, source headers, archive queries, integer cadence pairing, and the alternate-star split. We add fixed models and tests in later sectors.
- usesA fixed CCD model predicts QLP minus SPOC times within 0.05 seconds in 128 stars from TESS sectors 90–97
We use its integer relation between QLP and SPOC exposure labels and reuse its native FITS reader unchanged under MIT. Its sector 98 control motivates the small-baseline test.
- Six 2019 QLP time stamps for KIC 9832227 are 3.0 to 5.1 minutes early under archived time conventions
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.
- usesAn ecliptic frame model predicts relative Sector 85 time changes within 0.005 seconds in eight Camera 2 and 4 test stars
We use its exposure matching, wide sky selection, and separate training and test target methods in a new sector.
- The tested TESS sector 85 files for V459 Cas show a 120-second relative time jump
Prior relative QLP and SPOC time audit in sectors 98 to 104. It establishes prior use of exposure labels for time comparison.
- usesA fixed CCD and frame model predicts QLP minus TESS-SPOC times within 0.02 seconds in 96 sector 84–85 stars
We reuse its small native FITS reader under the MIT License. We preserve its author notice.
- usesFixed CCD offsets and proper motion predict QLP minus TESS-SPOC times within 3 milliseconds in 16 Sector 84 stars
We reuse its independent native FITS reader under the MIT License. We retain the original author notice.
- usesA fixed frame model predicts QLP minus TESS-SPOC times within 0.01 seconds in 16 sector 85 test stars after baseline calibration
We use its exposure-matching method and reuse its small native FITS reader unchanged under the MIT License. It also establishes prior relative time tests in later sectors.