TESS shows three 1 % transits of TIC 450075744 at P = 29.664 d, not at its 5.114 d Gaia DR3 SB1 period; centroids exclude the 9 arcsec neighbour; with FLAME values the 3.3 h transit needs e >= 0.55

Gaia DR3 gives a single-lined spectroscopic (SB1) orbit with P = 5.114 d and m2 sin i = 0.058 Msun for the G-type star TIC 450075744 (Gaia DR3 3288772766261941376, G = 12.2). TESS shows no transit at this period. TESS shows three transit-like dips of 0.9 % to 1.2 % depth instead: one in sector 5 (2018) and two in sector 98 (2025). The dips agree with one linear ephemeris, P = 29.664290 +- 0.000015 d, with timing residuals below 1 min. No dip occurs at the observed epochs of P/k (k = 2 to 12). The two sector-98 dips have the same depth, thus they are not a primary and a secondary eclipse of a 59.3 d binary. The flat-bottomed shape excludes an eclipsed star more than 0.97 mag fainter than the target. The flux centroids during the dips move toward the target (p = 0.11) and not toward the 9 arcsec neighbour (p = 1e-64). If the target is the eclipsed star, the transiting body has R = 1.09 to 1.16 R_Jup (a giant planet, a brown dwarf or a very-low-mass star). The 3.3 h transit needs a stellar density of 6.65 rho_sun in a circular orbit (3 sigma: >= 3.69), but the Gaia FLAME density is 0.58 rho_sun. Thus the orbit must be eccentric, with e >= 0.55 (3 sigma). A denser eclipsed star at the same distance is too faint. A 5.114 d companion and an eccentric 29.664 d body cannot both orbit the target in a stable configuration (Mardling & Aarseth 2001: a_out/a_in >= 8.7 is necessary; the actual ratio is 3.3). Simulated RV sets at the 51 Gaia field-of-view transits of the star gave the Gaia period for 0 of 200 circular 29.664 d orbits and for 5 of 4200 (0.1 %) eccentric orbits. This periodogram test is only a proxy for the Gaia pipeline. Thus the TESS dips and the Gaia SB1 orbit do not agree: the Gaia period is wrong, the Gaia orbit is spurious, or the system has a configuration that we did not test. On 2026-10-23 the star was not a TOI or CTOI. We give the next transit times (first: BJD_TDB 2461355.4210 +- 0.0007) and the expected RV amplitudes (0.87 km/s for 13 M_Jup). The package contains the TESS light curves, the code, the derived results and the download scripts.

TESS · Gaia DR3 · single-lined spectroscopic binary · transit candidate · TIC 450075744 · eccentric orbit · centroid test · blend test · hierarchical triple stability · brown dwarf · giant planet · period alias · QLP · TESS-SPOC