Gaia DR3 transit-table periods are sampling aliases for 161 of 174 known planets; TESS and Gaia epochs give true periods and five new non-TOI planet candidates among 40 unconfirmed sources

Question: Are the periods and reference times in the corrected Gaia DR3 planetary-transit table (gaiadr3.vari_planetary_transit, 214 sources) correct, and do TESS data confirm the unconfirmed candidates? Approach: We compared the table with literature ephemerides of the 174 sources that now host confirmed planets. We folded the Gaia DR3 G epoch photometry of all 214 sources at the table and literature ephemerides. We searched 992 TESS light curves (TESS-SPOC, QLP, SPOC; at most 8 sectors per source) with box least squares. We measured per-transit odd/even and phase-0.5 depths with empirical errors. We linked TESS signals to dimmed Gaia epochs with a trials-corrected scan. The same rules were applied to known planets to measure their false-flag rates. Results: The Gaia period agrees with the literature period for only 13 of 174 known planets. For these 13, the current reference times agree with the literature ephemeris; the withdrawn 2022 reference times agree for 1. For 158 of the other 161, the table ephemeris still selects significantly dimmed Gaia epochs, and a median of 75 percent of these epochs fall inside true transits. The table periods are therefore aliases that fit a median of 3 in-transit Gaia epochs. TESS detects all 173 observed known planets. Of the 40 unconfirmed sources, 13 show a planet-like TESS transit linked to the Gaia epochs (8 are TOIs; 5 are not TOIs and are new candidates, with periods of 1.615, 2.124, 2.208, 3.549 and 17.69 d), 10 show eclipsing-binary indicators (two with matching Gaia SB1/SB2 orbits), 7 show no TESS transit although TESS should detect the Gaia depth, 5 have no TESS light curve, and 5 are inconclusive. For 15 of 23 linked candidates the Gaia period is an alias. Limitations: No pixel-level vetting, no transit-model fits, box-depth radii, at most 8 TESS sectors per source, and a link test that succeeds for only 76 percent of known planets. The five new candidates need spectroscopic and high-resolution imaging follow-up.

Gaia DR3 · vari_planetary_transit · TESS · transiting exoplanets · period aliasing · eclipsing binaries · planet candidates · epoch photometry · catalogue validation · hot Jupiters