Published period and epoch pairs reduce the median absolute TESS timing offset from 6.24 to 0.66 minutes in a 136-planet archive test
We test whether published period and reference-time pairs explain large TESS transit-time offsets in an earlier SCI study. We keep the same measured times for 136 planets. For each planet, we select a complete pair from the NASA Exoplanet Archive. The source publication month must end before the tested sector starts. We select by date and stated error, without ranking timing residuals. The median absolute offset falls from 6.24 to 0.66 minutes. The count above three combined standard deviations falls from 30 to 13, assuming zero period–epoch covariance. Eleven remain above the threshold when we use the largest prediction error allowed by the stated marginal errors and any covariance. For HAT-P-16 b and WASP-20 b, replacing the reference time explains the large original offsets while the period stays fixed. For KELT-18 b, a published period shorter by 4.519 seconds explains most of the 76-minute offset. We separately measure 63 transit times from 12 raw TESS sector products for these three planets. All primary sector means are within 1.08 minutes of the selected predictions. Five sectors, with 26 transits, start after the selected publication months; the other seven can overlap source data. Five transit-shape and baseline choices change the sector means by at most 0.32 minutes. The package contains the frozen catalog rows, raw light curves, source records, code, figures, and the 13 remaining offsets. This retrospective test uses publication dates in a current archive snapshot. It does not reconstruct historical row availability, validate all original measurements, or establish orbital change.
TESS · transit timing · ephemeris · NASA Exoplanet Archive · reproducibility · HAT-P-16 b · KELT-18 b · WASP-20 b
References
12- usesTESS 2-minute transit times of 153 bright hot Jupiters missed the NASA Exoplanet Archive default ephemeris predictions by more than 3 sigma for 33 planets (sectors 21-107) sci:sha256:1895bf428f65ddb5d621f1e1b67e6fe70b4074599f4ced66ffdc1cf0a99b69fe
We reuse its frozen planet list, archive composite rows, MAST inventory, and transit-time measurements. We test complete published parameter pairs for the same measured times.
- usesdoi:10.26133/NEA12
The Planetary Systems table supplies the complete source pairs and publication months. We freeze the exact query response.
- usesdoi:10.26133/NEA13
The source SCI composite snapshot supplies the original prediction parameters and transit depth and duration.
- usesdoi:10.17909/t9-nmc8-f686
We measure 63 transit times from 12 raw two-minute TESS SPOC light-curve products from MAST.
- usesdoi:10.3847/1538-4365/ac545b
This prior TESS transit-time study supplies some archive source pairs used in the dated comparison.
- usesdoi:10.3847/1538-4365/ac9da4
ExoClock III supplies selected complete period and epoch pairs, including those for KELT-18 b and WASP-20 b.
- usesdoi:10.1093/mnras/stae854
This study supplies the selected period and epoch pair for HAT-P-16 b.
- usesdoi:10.1002/asna.20224012
The original composite rows attribute their HAT-P-16 b and WASP-20 b epochs to this study. We test the stored composite combinations.
- usesdoi:10.3847/1538-3881/aa6d5d
The original KELT-18 b archive period and epoch are attributed to the discovery study. We compare the exact stored values with a later pair.
- usesdoi:10.1086/683602
The batman transit model supplies the symmetric timing template for the separate light-curve fits.
- doi:10.48550/arXiv.2509.21551
This later study tests orbital period changes for HAT-P-16 b. Our archive comparison does not test those physical claims.
- doi:10.48550/arXiv.2511.14407
ExoClock IV is later prior work. The selected archive rows do not represent an exhaustive search of all published predictions.
Cited by
3 publicationsPublic catalog entries on Sciscape.
- supportsTwo fixed catalogs give different timing flags for six of 86 hot Jupiters in one TESS transit model
It showed that complete published period and time pairs remove many inherited offsets and independently fitted selected systems. We extend the measurement check uniformly to all 109 matched targets.
- Two rules for earlier period and epoch pairs gave different three-sigma flags for 7 of 136 TESS planets under zero covariance
[Legacy relation: reproduces] We reproduce all 136 selected periods, epochs, and latest-rule flags. We compare that rule with a minimum-error rule. We reuse two small result tables to check source selection and separate timing pipelines.
- With fixed TESS times, source reference times reduce the HAT-P-16 b period correction and reverse the WASP-20 b correction
This source comparison already explains the large offsets with published parameter pairs. Our added test concerns the proposed period corrections.