Public velocities select the 131.33-day period for TIC 63921468 among 60 TESS periods with one Kepler orbit and eccentricity at most 0.95

We test 60 periods that an earlier SCI study retained for two TESS transits of TIC 63921468. We use 28 public PLATOSpec radial velocities and one Kepler orbit, with eccentricity at most 0.95. The period near 131.33 days, or 22 cycles between TESS sectors 3 and 107, gives the lowest score under all three tested velocity noise models. With extra Gaussian noise fit to the data, the next period has a worse score by 145.31 in minus twice the log likelihood. This is a model comparison, not a posterior probability. The object is a known brown dwarf; we do not claim a new planet or a new transit detection. The later event agrees with its published orbit. Five transit timing models give period centers from 131.331876 to 131.333436 days. A change from a free transit shape to the published shape shifts the period by 2.23 minutes, much more than the formal error. The free shape reaches a limb-darkening bound, so a precise physical timing update is not supported. We reproduce the earlier weight of 0.00000321 for the selected period. Updating the density prior for the known eccentricity and stellar parameters still gives that period a very small weight on the same saved grid. A simple density correction does not resolve the conflict with the velocities. The package contains native data, input hashes, code, all 60 fits, timing controls, residual-shift tests, figures, and reproduction steps.

TESS · TIC 63921468 · brown dwarfs · radial velocities · period aliases · transit timing · model sensitivity · reproducibility