We update the fundamental physical and orbital properties of the transiting hot-Saturn type exoplanet HAT-P-19b and its host star HAT-P-19 as a result of the global modeling of our high-precision transit light curves , an archive spectrum , radial velocity observations , brightness values from broadband photometry in different passbands , and the precise distance of the system derived from its Gaia parallax .
We collected all the light curves obtained with ground-based photometry by amateur and professional observers , measured mid-transit times , analyzed their differences from calculated transit timings based on reference ephemeris information , which we update as a result .
We haven ’ t found any periodicity in the residuals of a linear trend , which we attribute to the accumulation of uncertainties in the reference mid-transit time and the orbital period .
We discuss the potential origins of the variation in transit timings briefly and find stellar activity as the most likely cause .
Finally , we comment on the scenarios describing the formation and migration of this hot-Saturn type exoplanet with a bloated atmosphere yet a small core , although it is orbiting a metal-rich ( [ Fe / H ] = 0.24 dex ) host star based on the planetary , orbital , and stellar parameters of the system that we derived from our global model , the age and the evolutionary history of the star .