Radial distribution of giant exoplanets at Solar System scales

Abstract

Aims. Giant planets play a major role in multiple planetary systems. Knowing their demographics is important to test their overall impact on the formation of planetary systems. It is also important to test their formation processes. Recently, three radial velocity (RV) surveys have established radial distributions of giant planets. All show a steep increase up to 1–3 au, and two suggest a decrease beyond that. Methods. We aim to understand the limitations associated with the characterization of long-period giant RV planets, and to estimate their impact on the radial distribution of these planets. Results. We revisit the results obtained by two major surveys that derived such radial distributions, using the RV data available at the time of the surveys as well as, whenever possible, new data. Conclusions. We show that the radial distributions published beyond (5–8 au) are not secure. More precisely, the decrease in the radial distribution beyond the peak at 1–3 au is not confirmed.