TESS transits after January 2023 support published period changes for WASP-12 b and HAT-P-7 b and reject them for 7 of 24 tested hot-Jupiter candidates
Wang et al. (2024) reported 26 hot Jupiters with a possible constant period change (dP/dt), with data up to January 2023. We measured 13,874 transit mid-times of 364 hot Jupiters in TESS SPOC 2-min light curves from sectors 1 to 107 (2018 to October 2026). For each candidate, we fitted a constant-period model (H0) and a model with the published dP/dt (H1) to vetted pre-TESS literature epochs and TESS sectors 1 to 60. Then we compared their forecasts with the TESS transits from sector 61 onward, which the original study did not use. 166 control planets calibrated the forecast errors with a 1-min literature-time floor (robust sigma of normalised offsets 0.93). Of the 24 candidates with test data, the new transits favour the published rate for WASP-12 b (delta chi2 = -194) and HAT-P-7 b (-31). They favour a constant period for 11 candidates, and for 7 of them in all 4 analysis variants: WASP-45 b, WASP-17 b, WASP-22 b, WASP-16 b, XO-3 b, WASP-46 b and HAT-P-43 b. 15 candidates, which include WASP-4 b and WASP-19 b, stay inconclusive. For WASP-12 b, we measure dP/dt = -34.6 +/- 2.0 ms/yr (Q'* about 1.7e5). HAT-P-7 b has a stable period increase of +30.9 +/- 4.4 ms/yr, which tides cannot cause and a Romer delay of about +49 m/s/yr can. In TESS data alone, KELT-20 b shows +58 +/- 12 ms/yr. This agrees with a recent brown-dwarf companion report, but the signal depends on one 2019 sector. In 208 well-measured planets, 7 have |z| > 3 (0.6 expected). If all period changes are tidal, a stack without WASP-12 b gives Q'* > 6e6 (95%), mostly from WASP-18 b. Limitations: literature epochs come from the archive table and not from re-fitted light curves, some test sets have fewer than 10 transits, and we used no radial velocities.
hot Jupiters · orbital decay · transit timing · TESS · tidal quality factor · WASP-12 b · HAT-P-7 b · KELT-20 b · Romer delay · out-of-sample test · ephemeris
References
7- uses, reviews, challenges, supportsdoi:10.3847/1538-4365/ad0847
We test its 26 period-change candidates with TESS data after January 2023. We use its published dP/dt values and its linear-ephemeris planets as controls.
- supportshttps://arxiv.org/abs/2606.02705
Our independent TESS timing of KELT-20 b gives a positive quadratic term that agrees with its light-travel-time signal, but it depends on one sector.
- doi:10.3847/1538-4365/ac545b
Earlier TESS timing study of hundreds of hot Jupiters.
- usesdoi:10.1086/683602
batman transit model.
- usesdoi:10.26133/NEA12
Planetary Systems Composite Parameters table for the sample.
- usesdoi:10.26133/NEA13
Planetary Systems table for pre-TESS literature epochs.
- useshttps://archive.stsci.edu/tess/
TESS SPOC 2-min light curves, sectors 1 to 107.
Cited by
3 publicationsPublic catalog entries on Sciscape.
- TESS 2-min light curves (2019-2026) show transit-duration trends in 6 of 120 planets around hot stars and 1 of 271 around cooler stars; WASP-167 b is a new nodal-precession candidate
Related campaign TESS 2-min hot-Jupiter timing study (period changes). This work measures durations instead.
- TESS data taken after submission show transits for 88% of testable community TOIs, but 67% of 1,978 CTOI ephemerides no longer locate the transit (sectors to 107, 2026)
Related campaign study of TESS transit timing against published ephemerides.
- TESS eclipse times confirm the timing drifts of most of 27 apsidal-motion circumbinary-planet candidates, but measured radii make tides sufficient for 9 and leave a clear excess in 4
Related campaign study: forecast test of reported orbital period changes with TESS timing.