Filling the mass-radius diagram with HARPS-N
To understand the variety, formation, and dynamics of exoplanetary systems, we can study their mass-radius relationship. Kepler and K2 have discovered thousands of exoplanet candidates providing precise planetary radii. High-resolution radial velocity follow up is then needed to determine a precise mass and hence a bulk density. Very precise planetry masses are determined only with many observations and advanced computational efforts. To get a close-to-complete picture of the planet population, it is furthermore important to also include upper limits of exoplanet masses where stellar activity, stellar brightness or other factors make a more precise measurement much harder. In this talk I will give an overview of the HARPS-N GTO Science Team's efforts to fill the mass-radius diagram, including recent results on K2 planets and upper limits for some Kepler planets.