Double Hot Jupiter Formation through Mirrored ZLK Migration in Binary Star Systems: The Case of WASP-94

TL;DR

This paper demonstrates through N-body simulations that the double hot Jupiter system WASP-94 can be explained by mirrored von Zeipel-Lidov-Kozai migration, highlighting the stochastic nature of planet formation in twin binary systems.

Contribution

It introduces a novel migration mechanism to explain the formation of double hot Jupiters in twin binary star systems, supported by simulations of the WASP-94 system.

Findings

Double hot Jupiters can form via mirrored ZLK migration.

Simulations reproduce the observed configuration of WASP-94.

Gaia data may reveal more twin planetary systems.

Abstract

To date, only a handful of binary star systems are known with at least one confirmed planet orbiting each star. Such systems, however, offer a unique perspective on the stochasticity intrinsic to planet formation and evolution -- particularly in twin binary star systems, which consist of near-equal-mass stars formed contemporaneously in the same birth environment. The WASP-94 system, which includes twin F-type stars, is a striking exemplar of such systems, containing two hot Jupiters: WASP-94 Ab is a transiting, spin-orbit misaligned giant planet with a 4-day orbital period, while WASP-94 Bb is non-transiting and has a tighter 2-day orbital period. In this work, we leverage N-body simulations to show that the current double hot Jupiter configuration of the WASP-94 system can be reproduced through mirrored von Zeipel-Lidov-Kozai migration. The upcoming Gaia astrometric data releases offer the potential to search for additional twin planetary systems, including double cold Jupiter systems that may serve as the progenitors for WASP-94-like configurations.