2023/12/12 by Lee J. Rosenthal, Andrew W. Howard, Heather A. Knutson +1 · 16 citations
Earth and Planetary Sciences · Physics and Astronomy · #Astro and Planetary Science #Astronomy #Astrophysics #Eccentricity (behavior) #Exoplanet #Gas giant #Giant planet #Giant star #High-pressure geophysics and materials #Jupiter (rocket family) #Orbital eccentricity #Physics #Planet #Planetary system #Red giant #Stars #Stellar, planetary, and galactic studies
paper · pdf · doi:10.3847/1538-4365/acffc0
published in The Astrophysical Journal Supplement Series 270(1), 1 (Institute of Physics)
openalex publication_date 2023/12/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
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 to e = 0.47 (90th percentile), while the single giant planets have a pileup of nearly circular orbits and a long tail that extends to e = 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 ∼2.3 σ significant hot Jupiter ( a < 0.06) pileup not seen among multigiant systems. We find that the median mass ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>M</mml:mi> <mml:mi>sin</mml:mi> <mml:mi>i</mml:mi> </mml:math> ) of giants in multiples is nearly double that of single giants (1.71 M J versus 0.92 M J ). 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.