Work

Dynamical Constraints on the Origin of Hot and Warm Jupiters With Close Friends

Year: 2016

Type: article

Abstract: ABSTRACT Gas giants orbiting their host star within the ice line are thought to have migrated to their current locations from farther out. Here we consider the origin and dynamical evolution of observed Jupiters, focusing on hot and warm Jupiters with outer friends. We show that the majority of the observed Jupiter pairs (20 out of 24) are dynamically unstable if the inner planet is placed at ≳1 au distance from the stellar host. This finding is at odds with formation theories that invoke the migration of such planets from semimajor axes ≳1 au due to secular dynamical processes (e.g., secular chaos, Lidov–Kozai [LK] oscillations) coupled with tidal dissipation. In fact, the results of N-body integrations show that the evolution of dynamically unstable systems does not lead to tidal migration but rather to planet ejections and collisions with the host star. This and other arguments lead us to suggest that most of the observed planets with a companion could not have been transported from farther out through secular migration processes. More generally, by using a combination of numerical and analytic techniques, we show that the high-e LK migration scenario can only account for less than 10% of all gas giants observed between 0.1 and 1 au. Simulations of multiplanet systems support this result. Our study indicates that rather than starting on highly eccentric orbits with orbital periods above 1 yr, these “warm” Jupiters are more likely to have reached the region where they are observed today without having experienced significant tidal dissipation.

Source: The Astronomical Journal

DOI: 10.3847/0004-6256/152/6/174

Authors: Fabio Antonini, Adrian S. Hamers, Yoram Lithwick

Institutions: Northwestern University, Leiden Observatory

Language: English

Topic: Stellar, planetary, and galactic studies

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: bronze

Funders: National Science Foundation, National Aeronautics and Space Administration, Northwestern University, Nederlandse Organisatie voor Wetenschappelijk Onderzoek

Awards: The Final Parsec: Multi-Scale Simulations of Supermassive Black-Hole Coalescence in Galaxy Mergers, A Little Green Machine for High Performance Parallel Multipurpose Supercomputing Using Graphical Processing Units, CAREER: Planet Formation in the Age of Kepler, G6473302934, THE THEORY FOR HOW PLANETARY SYSTEMS FORM AND ACHIEVE THEIR FINAL CONFIGURATION REMAINS HIGHLY UNCERTAIN. UNTIL NOW, THEORIES COULD ONLY BE TESTED AG