A Spectroscopic Analysis of the California-Kepler Survey Sample: II. Correlations of Stellar Metallicities with Planetary Architectures

Abstract

We present independent and self-consistent metallicities for a sample of 807 planet-hosting stars from the California-Kepler Survey from an LTE spectroscopic analysis using a selected sample of Fe I and Fe II lines. Correlations between host-star metallicities, planet radii, and planetary architecture (orbital periods - warm or hot - and multiplicity - single or multiple), were investigated using non-parametric statistical tests. In addition to confirming previous results from the literature, e.g., that overall host star metallicity distributions differ between hot and warm planetary systems of all types, we report on a new finding that when comparing the median metallicities of hot versus warm systems, the difference for multiple Super-Earths is considerably larger when compared to that difference in single Super-Earths. The metallicity CDFs of hot single Super-Earths versus warm single Super-Earths indicate different parent stellar populations, while for Sub-Neptunes this is not the case. The transition radius between Sub-Neptunes and Sub-Saturns was examined by comparing the APOGEE metallicity distribution for the Milky Way thin disk in the solar neighborhood with metallicity distributions of host stars segregated based upon the largest known planet in their system. These comparisons reveal increasingly different metallicity distributions as the radius of the largest planet in the systems increases, with the parent stellar metallicities becoming significantly different for R${}_p>$ 2.7 R${}_{\oplus }$. The behavior of the p-values as a function of planet radius undergoes a large slope change at R${}_p$ = 4.4 $\pm$ 0.5 R${}_{\oplus }$, indicating the radius boundary between small and large planets.

Accepted for publication in ApJ

References in corpus (15)

• Array Programming with NumPy
• Spectroscopic parameters for 451 stars in the HARPS GTO planet search program. Stellar [Fe/H] and the frequency of exo-Neptunes
• Three regimes of extrasolar planets inferred from host star metallicities
• ARES v2 - new features and improved performance
• Stellar Parameters and Metallicities of Stars Hosting Jovian and Neptunian Mass Planets: A Possible Dependence of Planetary Mass on Metallicity
• The APOGEE Data Release 16 Spectral Line List
• Activity indicators and stellar parameters of the Kepler targets. An application of the ROTFIT pipeline to LAMOST-Kepler stellar spectra
• A Spectroscopic Analysis of the California-Kepler Survey Sample: I. Stellar Parameters, Planetary Radii and a Slope in the Radius Gap
• LAMOST telescope reveals that Neptunian cousins of hot Jupiters are mostly single offspring of stars that are rich in heavy elements
• A Super-Solar Metallicity For Stars With Hot Rocky Exoplanets
• Heavy metal rules. I. Exoplanet incidence and metallicity
• Current Population Statistics Do Not Favor Photoevaporation over Core-Powered Mass Loss as the Dominant Cause of the Exoplanet Radius Gap
• A Continuum of Planet Formation Between 1 and 4 Earth Radii
• Elemental Abundances of Kepler Objects of Interest in APOGEE. I. Two Distinct Orbital Period Regimes Inferred from Host Star Iron Abundances
• LAMOST observations in the Kepler field. Analysis of the stellar parameters measured with the LASP based on the low-resolution spectra

Cited by in corpus (10)

• How the origin of stars in the Galaxy impacts the composition of planetary building blocks
• ODUSSEAS: Upgraded version with new reference scale and parameter determinations for 82 planet-host M dwarf stars in SWEET-Cat
• The Influence of 10 Unique Chemical Elements in Shaping the Distribution of Kepler Planets
• Updated Catalog of Kepler Planet Candidates: Focus on Accuracy and Orbital Periods
• A Spectroscopic Analysis of a Sample of K2 Planet-Host Stars: Stellar Parameters, Metallicities and Planetary Radii
• A comprehensive study of the relations between the properties of planetary systems and the chemical compositions of their host stars
• TOI-3568 b: a super-Neptune in the sub-Jovian desert
• Elemental Abundances of Kepler Objects of Interest in APOGEE DR17
• rrlfe: Software for Generating and Applying Metallicity Calibrations for RR Lyrae Variable Stars Across a Wide Range of Phases and Temperatures
• The SOL $\text{(Solar Origin and Life)}$ Project: Detailed characterization of candidates for the ZAMS and Subgiant stages