TESS data show transits at the radial-velocity period of TOI-1117 c and exclude most transits of 423 other radial-velocity planets with periods up to 100 days

Question: do TESS 2-minute light curves show transits at the known periods of planets that radial-velocity (RV) surveys found, and where do the data exclude transits? Method: we searched the light curves (sectors 1-107, 2018-2026) of 448 RV planets with P <= 100 d on 332 hosts. We used a phase-binned box statistic near each RV period, the RV conjunction prior when available, control periods, and an exclusion test calibrated with 4,230 injected transits (1 false exclusion in 3,983 covered injections). Results: (1) TOI-1117 c, which the discovery paper classified as non-transiting, shows a 471 +- 52 ppm, 1.9 h dip at P = 4.578646 +- 0.000035 d, equal to the RV period (4.579 +- 0.004 d). The dip is consistent in all 2-minute sectors, in odd and even events and in SAP flux, and the centroid does not move. 0 of 2,000 random periods reach its SNR. Sector 13 (2019) data that we did not use in the search show the dip at the predicted times in three pipelines (440-685 ppm; p < 0.001 each). The implied radius is about 2.5 Earth radii. We call it a strong transit candidate, not a confirmed transit. (2) For 324 of 423 non-transiting RV planets, the data exclude at 3 sigma at least 90% of the RV-prior conjunction probability for transits of half or more of the predicted depth (b < 0.87). (3) In 381 RV-selected planets, geometry predicts 19.8 transiting planets and the search recovers the 16 known ones (p = 0.22). (4) The other 11 screened signals are systematics, blends, or the known synchronized spot modulation of HD 41004 B. Limitations: predicted depths use mass-radius estimates; grazing transits are not tested; TOI-1117 c needs a dedicated transit observation and a joint fit.

TESS · radial velocity planets · transit search · TOI-1117 · transit exclusion · injection recovery · HD 41004 · stellar rotation · sub-Neptune · known-period search