On the shoulders of giants

Cold Jupiters and their role in the formation of inner low-mass planets. From theory to observations

25-26-27 March 2026

Turin

Although gas giants were the first exoplanets to be discovered in close orbits, only in the last five years has it been possible to make detailed statistical studies of cold Jupiters, i.e., gaseous giant planets with orbital separation between 1 and 10 AU like Jupiter. These studies were mainly based on high precision radial-velocity measurements over several years. A key contribution is expected soon from high-precision Gaia astrometry (Gaia DR4).

The properties of cold Jupiters (eccentricity, multiplicity, occurrence rates as a function of metallicity and stellar mass) provide fundamental information on the formation and evolution of planetary systems and their possible terrestrial planets. Interactions among giant planets after the dissipation of the protoplanetary disk (planet-planet scattering) may strongly influence the formation of terrestrial planets in the habitable zone and/or inner regions. On the other hand, some studies pointed to the possible beneficial role of Jupiter in protecting our Earth from potentially life-destroying asteroid and/or short-period comet impacts.

The study of the relation between cold Jupiters and inner small planets, i.e., sub-Neptunes and super-Earths in short period orbits (P < 100 d), is a frontier topic for today's exoplanetary science. Planet formation simulations obtained discordant results, predicting negative, null or positive correlations between the two planetary populations, depending on the different formation models and/or model parameters adopted. Some disagreement is also present in observational results from different radial velocity surveys.

Crucial questions on the relation between cold Jupiters and small and terrestrial planets still remain unanswered: do outer gaseous giants promote or inhibit the formation of inner low-mass close-in planets, or do they have a substantially negligible impact on it? Can the absence of sub-Neptunes and super-Earths in the Solar System be attributed to the presence of Jupiter and Saturn? To what extent does the emergence of life depend on the presence of a Jupiter analogue?

The proposed international workshop aims to bring together leaders in both the observational and theoretical fields to discuss all of these issues, leading to fundamental advances in the field while charting new directions for future research and observational campaigns.

SOC: Eleonora Alei (NASA Goddard Space Flight Center, USA), Domenico Barbato (INAF-Padova, Italy), Aldo S. Bonomo (INAF-Torino, Italy), Silvano Desidera (INAF-Padova, Italy), Rachel Fernandes (Penn State University, USA), Benjamin Fulton (California Institute of Technology, USA), Heather Knutson (California Institute of Technology, USA), Anne-Marie Lagrange (LESIA, France), Michiel Lambrechts (University of Copenhagen, Denmark), Yamila Miguel (Leiden Observatory & SRON, the Netherlands), Alessandro Morbidelli (Observatoire de la Côte d’Azur, France), Damien Ségransan (University of Geneva, Switzerland), Alessandro Sozzetti (INAF-Torino, Italy), Robert Wittenmyer (University of Southern Queensland, Australia)

LOC: Aldo S. Bonomo, Ilaria Carleo, Mario Damasso, Gloria Guilluy, Francesca Manni, Luca Naponiello, Matteo Pinamonti, Alessandro Ruggieri