PHANTOM Candidate TIC 181856484: A 5.47880-Day Transit Signal in TESS Photometry

Status: planet candidate. A periodic transit-like signal on TIC 181856484 found by PHANTOM (Planet Hunting Across Noisy TESS Observations and Measurements), an independent search of NASA TESS photometry. It has not been confirmed as a planet: its source star and nature are not yet established by follow-up observations (see Unresolved). Version 1.0 of this record. TIC: 181856484 Star: Tmag 14.70, Teff 3419 K, radius 0.386 ± 0.012 R☉, distance 153.6 pc (TIC v8) Period: 5.478799 ± 0.000010 d Mid-transit epoch: BJD_TDB 2459574.8897 ± 0.0015 Depth: 22,614 ± 1,263 ppm Duration: 2.22 ± 0.13 h Radius if on the target: 6.26 +0.24/−0.24 R⊕ (the detailed review's physical fit with the star's density as a prior: its Rp/Rs × the TIC stellar radius, both uncertainties) Transits meeting the fit's coverage criterion: 23 in TESS sectors 10, 37, 46, 63, 90, 91 Detection S/N: 24.6 (PHANTOM's search) Open questions (README.md, Unresolved): The transit implies a stellar density below the TIC's; The location of the dip rests on the difference images, which test the Gaia stars they list; No radial-velocity measurement; Not statistically validated. The full record, with the evidence, uncertainties, data sources, cross-matches, unresolved questions and publication history, is README.md in this deposit.