Hot Jupiter formation in dense clusters: secular chaos in multiplanetary systems
ABSTRACT

Exoplanetary observations reveal that the occurrence rate of hot Jupiters is correlated with star clustering. In star clusters, interactions between planetary systems and close flyby stars can significantly change the architecture of primordially coplanar, circular planetary systems. Flybys can impact hot Jupiter formation via activation of high-eccentricity excitation mechanisms such as the Zeipel–Lidov–Kozai (ZLK) effect and planet–planet scattering. Previous studies have shown that, for a two-planet system, close flybys, especially at high incidence angles, can efficiently activate the ZLK mechanism, thus triggering high-eccentricity tidal migration and ultimately form hot Jupiters. Here, we extend our previous study with a multiplanet (triple) system. We perform high-precision, high-accuracy few-body simulations of stellar flybys and subsequent planetary migration within the perturbed planetary systems using the code spacehub. Our simulations demonstrate that a single close flyby on a multiplanet system can activate secular chaos and ultimately lead to hot Jupiter formation via high-eccentricity migration. We find that the hot Jupiter formation rate per system increases with both the size of the planetary system and the mass of the outer planet, and we quantify the relative formation fractions for a range of parameters. Hot Jupiters formed via secular chaos are expected to be accompanied by more »

Authors:
; ; ;
Publication Date:
NSF-PAR ID:
10381234
Journal Name:
Monthly Notices of the Royal Astronomical Society
Volume:
509
Issue:
4
Page Range or eLocation-ID:
p. 5253-5264
ISSN:
0035-8711
Publisher:
Oxford University Press
National Science Foundation
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1. Abstract

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2. ABSTRACT

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3. Abstract

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5. Abstract

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