Is the orbit of WASP-19 b decaying?

Transit timing variations (TTVs) have proven to be a very valuable tool in the field of exoplanetary detection. Currently, WASP-4 and WASP-12 stand out as the most promising candidates exhibiting TTVs. We have presented here the transit timing variation analysis of the exoplanet WASP-19 b, one of the first detected ultra-short-period gas-giant planets. For this, we have considered a total of 250 complete transits, which include 116 light curves from the Transiting Exoplanet Survey Satellite (TESS), 62 complete transit light curves from the Exoplanet Transit Database, and 72 others from the literature, covering a 13-year baseline. We found a TTV of amplitude 66.83 s and we further investigated the possible origin of the observed TTV. To assess the short-term TTV, we computed the false alarm probability (FAP) corresponding to the highest power peak using the generalized Lomb-Scargle periodogram: the calculated FAP value is 15%. Due to the lack of periodicity, we excluded short-term TTVs and looked for long-term TTVs. The orbital decay appears to be the most plausible cause for the observed TTV and, in order to confirm these findings, further high-precision transit observations of the system would be worthwhile.