Speaker
Description
Precise planetary mass measurements are essential for constraining the internal structure and atmospheric properties of exoplanets. In the framework of the ESA Ariel mission, accurate masses are required to break key degeneracies in atmospheric retrievals. Estimating the observational effort needed to reach the desired mass precision is therefore crucial for the optimisation of current and future radial velocity (RV) surveys. To address this, we developed MINERVA, a tool designed to estimate the minimum number of RV observations required to measure the mass of transiting planets with a given precision. The code simulates RV time series for targets orbiting FGKM-type stars, accounting for instrumental noise, stellar activity, and realistic temporal sampling. It builds upon a synthetic stellar population representative of the solar neighborhood, assigning age, rotation, and magnetic activity through empirical calibrations, and converts the resulting activity levels into RV jitter amplitudes. As part of the code development, we derived a new empirical calibration between chromospheric activity and RV dispersion specifically for K-type stars, based on data from the GAPS and ArMS programs. We successfully validated MINERVA on individual targets with known planetary masses, yielding predictions for the required observational effort that are highly consistent with the values reported in the literature. Finally, to demonstrate its capability on statistically significant samples, we applied the code to a subsample extracted from the Ariel Mission Candidate Sample. Adopting HARPS-N@TNG as the reference instrument, we estimated the total number of observing nights required to achieve a planetary mass precision of 30%, providing a highly optimized observational roadmap for robust atmospheric retrievals.