Overcoming stellar activity in the transit and eclipse-timing variation analysis of WASP-52 b: updated orbital and system parameters, and ephemerides

Precise ephemeris and system parameters of transiting exoplanets are critical parameters for efficient scheduling of transiting exoplanet observations from space missions like James Webb Space Telescope, Pandora SmallSat, and ARIEL. We present updated system parameters and further investigate previously suggested long-term transit timing variation for the transiting hot Jupiter WASP-52 b, orbiting an active star of type K2V, known for displaying spot crossing events during transit observations. In this work, we performed a homogeneous analysis to refine the ephemeris and system paramaters for WASP-52 b, followed by a transit-timing variation analysis in search for period variations. We employed an updated version of the EXOTIC code and dynamic nested sampling to perform a joint fit of photometric and radial velocity observations, and strategies to mitigate the contamination from stellar activity present in the data. The dataset spans 10 years of transit monitoring from 105 ground-based observations by citizen science contributors employing sub-meter telescopes, together with transit and eclipse light curves from space missions, and archival ephemerides and radial velocity data from the literature.