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Title: The California Legacy Survey. IV. Lonely, Poor, and Eccentric: A Comparison between Solitary and Neighborly Gas Giants
Abstract

We compare systems with single giant planets to systems with multiple giant planets using a catalog of planets from a high-precision radial velocity survey of FGKM stars. Our comparison focuses on orbital properties, planet masses, and host-star properties. We use hierarchical methods to model the orbital eccentricity distributions of giant singles and giant multiples, and find that the distributions are distinct. The multiple giant planets typically have moderate eccentricities and their eccentricity distribution extends toe= 0.47 (90th percentile), while the single giant planets have a pileup of nearly circular orbits and a long tail that extends toe= 0.77. We determine that the stellar hosts of multiple giants are distinctly more metal rich than the hosts of solitary giants, with respective mean metallicities of 0.228 ± 0.027 versus 0.129 ± 0.019 dex. We measure the distinct occurrence distributions of single and multiple giants with respect to orbital separation, and find that single gas giants have a ∼2.3σsignificant hot Jupiter (a< 0.06) pileup not seen among multigiant systems. We find that the median mass (Msini) of giants in multiples is nearly double that of single giants (1.71MJversus 0.92MJ). We find that giant planets in the same system have correlated masses, analogous to the “peas in a pod” effect seen among less-massive planets.

 
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NSF-PAR ID:
10479240
Author(s) / Creator(s):
; ; ;
Publisher / Repository:
DOI PREFIX: 10.3847
Date Published:
Journal Name:
The Astrophysical Journal Supplement Series
Volume:
270
Issue:
1
ISSN:
0067-0049
Format(s):
Medium: X Size: Article No. 1
Size(s):
["Article No. 1"]
Sponsoring Org:
National Science Foundation
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