The California-Kepler Survey. IV. Metal-rich Stars Host a Greater Diversity of Planets

By E. Petigura, G. Marcy, J. Winn, L. Weiss, B. Fulton, Andrew W. Howard, E. Sinukoff, H. Isaacson, Timothy Morton, J. Johnson. 2017

270 citations recorded by the source corpus.

Probing the connection between a star’s metallicity and the presence and properties of any associated planets offers an observational link between conditions during the epoch of planet formation and mature planetary systems. We explore this connection by analyzing the metallicities of Kepler target stars and the subset of stars found to host transiting planets. After correcting for survey incompleteness, we measure planet occurrence: the number of planets per 100 stars with a given metallicity M. Planet occurrence correlates with metallicity for some, but not all, planet sizes and orbital periods. For warm super-Earths having P = 10–100 days and = 1.0–1.7 , planet occurrence is nearly constant over metallicities spanning −0.4 to +0.4 dex. We find 20 warm super-Earths per 100 stars, regardless of metallicity. In contrast, the occurrence of warm sub-Neptunes ( = 1.7–4.0 ) doubles over that same metallicity interval, from 20 to 40 planets per 100 stars. We model the distribution of planets as , where β characterizes the strength of any metallicity correlation. This correlation steepens with decreasing orbital period and increasing planet size. For warm super-Earths β = , while for hot Jupiters β = . High metallicities in protoplanetary disks may increase the mass of the largest rocky cores or the speed at which they are assembled, enhancing the production of planets larger than 1.7 . The association between high metallicity and short-period planets may reflect disk density profiles that facilitate the inward migration of solids or higher rates of planet–planet scattering.

Subfields: Astronomy and Astrophysics, Instrumentation, Statistical and Nonlinear Physics

View Paper: https://www.semanticscholar.org/paper/f1a33bb49e9018f918905464e075fc4eba340ab5

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. J. Owen
2. B. Fulton
3. D. Lai
4. E. Petigura
5. M. Moe
6. G. Mulders
7. Ilaria Pascucci
8. C. Badenes

In Instrumentation

1. J. Owen
2. B. Fulton
3. E. Petigura
4. D. Lai
5. Ilaria Pascucci
6. G. Mulders
7. D. Apai
8. C. Badenes

In Statistical and Nonlinear Physics

1. J. Owen
2. C. Badenes
3. B. Fulton
4. B. Gaudi
5. E. Petigura
6. M. Moe
7. Ilaria Pascucci
8. G. Mulders

Citations in the corpus

• Photoevaporation and high-eccentricity migration created the sub-Jovian desert (2018, background): “Recently, it has also been identified that the small (Neptune/sub-Neptune sized) planets close to the lower boundary are more common around higher metallicity stars (Dong et al. 2017; Petigura et al. 2018).”
• Predictions of the WFIRST Microlensing Survey. I. Bound Planet Detection Rates (2018, background): “Results from Kepler show a similar rising trend for large planets, but a shallow decline in occurrence beyond P∼10 d for planets smaller than Neptune (e.g. Petigura et al. 2018); whether these trends continue throughout WFIRST’s region of sensitivity is unconstrained at present.”
• The Close Binary Fraction of Solar-type Stars Is Strongly Anticorrelated with Metallicity (2018, background): “Hot Jupiters, Neptunes, and super-Earths with P<10 days are all significantly weighted toward metalrich hosts with [Fe/H]>0.0 (Fischer & Valenti 2005; Mulders et al. 2016; Owen & Murray-Clay 2018; Petigura et al. 2018).”
• The Exoplanet Population Observation Simulator. I. The Inner Edges of Planetary Systems (2018, methodology): “We evaluate the survey as a whole, and do not consider dependencies on stellar properties such as stellar mass (Mulders et al. 2015a, 2015b) or metallicity (Mulders et al. 2016; Petigura et al. 2018).”
• The California-Kepler Survey. VII. Precise Planet Radii Leveraging Gaia DR2 Reveal the Stellar Mass Dependence of the Planet Radius Gap (2018, background): “Indeed, Petigura et al. (2018) observed a correlation between planet size and host-star metallicity in the CKS sample, and this correlation has been observed previously in many different samples (e.g., Santos et al. 2004; Fischer & Valenti 2005; Sousa et al. 2008; Ghezzi et al. 2010; Buchhave et…”