Scaling K2. III. Comparable Planet Occurrence in the FGK Samples of Campaign 5 and Kepler

Abstract

Using our K2 Campaign 5 fully automated planet detection data set (43 planets), which has corresponding measures of completeness and reliability, we infer an underlying planet population model for the FGK dwarfs sample (9,257 stars). Implementing a broken power-law for both the period and radius distribution, we find an overall planet occurrence of $1.00_{-0.51}^{+1.07}$ planets per star within a period range of 0.5-38 days. Making similar cuts and running a comparable analysis on the Kepler sample (2,318 planets; 94,222 stars), we find an overall occurrence of $1.10\pm 0.05$ planets per star. Since the Campaign 5 field is nearly 120 angular degrees away from the Kepler field, this occurrence similarity offers evidence that the Kepler sample may provide a good baseline for Galactic inferences. Furthermore, the Kepler stellar sample is metal-rich compared to the K2 Campaign 5 sample, thus a finding of occurrence parity may reduce the role of metallicity in planet formation. However, a weak ($1.5\sigma$) difference, in agreement with metal-driven formation, is found when assuming the Kepler model power-laws for the K2 Campaign 5 sample and optimizing only the planet occurrence factor. This weak trend indicates further investigation of metallicity dependent occurrence is warranted once a larger sample of uniformly vetted K2 planet candidates are made available.

arXiv comment17 pages; 10 figures; 1 table; accepted for publication in AJ

References in corpus (68)

• emcee: The MCMC Hammer
• Gaia Data Release 2. Summary of the contents and survey properties
• PARSEC: stellar tracks and isochrones with the PAdova and TRieste Stellar Evolution Code
• The K2 Mission: Characterization and Early results
• The Geneva-Copenhagen survey of the Solar neighbourhood: Ages, metallicities, and kinematic properties of 14,000 F and G dwarfs
• The California-Kepler Survey. III. A Gap in the Radius Distribution of Small Planets
• Planet Occurrence within 0.25 AU of Solar-type Stars from Kepler
• The false positive rate of Kepler and the occurrence of planets
• Prevalence of Earth-size planets orbiting Sun-like stars
• Architecture and Dynamics of Kepler's Candidate Multiple Transiting Planet Systems
• The evaporation valley in the Kepler planets
• Overview of the Kepler Science Processing Pipeline
• The Occurrence Rate of Small Planets around Small Stars
• Chemical Cartography with APOGEE: Metallicity Distribution Functions and the Chemical Structure of the Milky Way Disk
• The Role of Core Mass in Controlling Evaporation: the Kepler Radius Distribution and the Kepler-36 Density Dichotomy
• Planetary Candidates Observed by Kepler. VIII. A Fully Automated Catalog With Measured Completeness and Reliability Based on Data Release 25
• Sculpting the Valley in the Radius Distribution of Small Exoplanets as a by-product of Planet Formation: The Core-Powered Mass-Loss Mechanism
• Terrestrial Planet Occurrence Rates for the Kepler GK Dwarf Sample
• The Frequency of Hot Jupiters Orbiting Nearby Solar-Type Stars
• The California-Kepler Survey V. Peas in a Pod: Planets in a Kepler Multi-planet System are Similar in Size and Regularly Spaced
• Stellar Spin-Orbit Misalignment in a Multiplanet System
• Almost All of Kepler's Multiple Planet Candidates are Planets
• The K2 Ecliptic Plane Input Catalog (EPIC) and Stellar Classifications of 138,600 Targets in Campaigns 1-8
• WASP-47: A Hot Jupiter System with Two Additional Planets Discovered by K2
• Exoplanet population inference and the abundance of Earth analogs from noisy, incomplete catalogs
• The Derivation, Properties and Value of Kepler's Combined Differential Photometric Precision
• Kepler constraints on planets near hot Jupiters
• The Exoplanet Population Observation Simulator. I - The Inner Edges of Planetary Systems
• Architecture of Planetary Systems Based on Kepler Data: Number of Planets and Coplanarity
• Planetary Candidates from the First Year of the K2 Mission
• The Exoplanet Census: A General Method, Applied to Kepler
• 197 Candidates and 104 Validated Planets in K2's First Five Fields
• Occurrence Rates of Planets orbiting FGK Stars: Combining Kepler DR25, Gaia DR2 and Bayesian Inference
• Kepler Planet Occurrence Rates for Mid-Type M Dwarfs as a Function of Spectral Type
• Kepler Multi-Planet Systems Exhibit Unexpected Intra-system Uniformity in Mass and Radius
• A Statistical Reconstruction of the Planet Population Around Kepler Solar-Type Stars
• Identification of Background False Positives from Kepler Data
• 275 Candidates and 149 Validated Planets Orbiting Bright Stars in K2 Campaigns 0-10
• Architectures of Exoplanetary Systems. I: A Clustered Forward Model for Exoplanetary Systems around Kepler's FGK Stars
• Most Sub-Arcsecond Companions of Kepler Exoplanet Candidate Host Stars are Gravitationally Bound
• Can planetary instability explain the Kepler dichotomy?
• Overabundance of alpha-elements in exoplanet host stars
• Scaling K2. I. Revised Parameters for 222,088 K2 Stars and a K2 Planet Radius Valley at 1.9 $R_{\oplus }$
• Stellar Companions of Exoplanet Host Stars in K2
• New planetary and EB candidates from Campaigns 1-6 of the K2 mission
• Measuring the Recoverability of Close Binaries in Gaia DR2 with the Robo-AO Kepler Survey
• Transiting exoplanet candidates from K2 Campaigns 5 and 6
• Terrestrial, Habitable-Zone Exoplanet Frequency from Kepler
• Characterizing K2 Candidate Planetary Systems Orbiting Low-Mass Stars II: Planetary Systems Observed During Campaigns 1-7
• Discovery of the Transiting Planet Kepler-5b
• Measuring Transit Signal Recovery in the Kepler Pipeline II: Detection Efficiency as Calculated in One Year of Data
• On the Metallicities of Kepler Stars
• Accounting for Incompleteness due to Transit Multiplicity in Kepler Planet Occurrence Rates
• A Probabilistic Approach to Kepler Completeness and Reliability for Exoplanet Occurrence Rates
• The Occurrence Rate of Earth Analog Planets Orbiting Sunlike Stars
• The K2-HERMES Survey: Age and Metallicity of the Thick Disc
• 44 Validated Planets from K2 Campaign 10
• Detection of Hundreds of New Planet Candidates and Eclipsing Binaries in K2 Campaigns 0-8
• The metallicity distribution and hot Jupiter rate of the Kepler field: Hectochelle High-resolution spectroscopy for 776 Kepler target stars
• Current Population Statistics Do Not Favor Photoevaporation over Core-Powered Mass Loss as the Dominant Cause of the Exoplanet Radius Gap
• Ultra Short Period Planets in K2: SuPerPiG Results for Campaigns 0-5
• The Exoplanet Population Observation Simulator. II -- Population Synthesis in the Era of Kepler
• Planet Candidates from K2 Campaigns 5-8 and Follow-Up Optical Spectroscopy
• Accounting for Multiplicity in Calculating Eta Earth
• Planetary Candidates from K2 Campaign 16
• Scaling K2. II. Assembly of a Fully Automated C5 Planet Candidate Catalog Using EDI-Vetter
• Examining the Radius Valley: a Machine Learning Approach
• Catalog of New K2 Exoplanet Candidates from Citizen Scientists

Cited by in corpus (12)

• Photoevaporation vs. core-powered mass-loss: model comparison with the 3D radius gap
• Caught in the Act: Core-powered Mass-loss Predictions for Observing Atmospheric Escape
• Scaling K2. VI. Reduced Small Planet Occurrence in High Galactic Amplitude Stars
• Exoplanets in the Galactic context: Planet occurrence rates in the thin disk, thick disk and stellar halo of Kepler stars
• Scaling K2. IV. A Uniform Planet Sample for Campaigns 1-8 and 10-18
• Scaling K2 VII: Evidence for a high occurrence rate of hot sub-Neptunes at intermediate ages
• Mapping the Skies of Ultracool Worlds: Detecting Storms and Spots with Extremely Large Telescopes
• A Unified Spectroscopic and Photometric Model to Infer Surface Inhomogeneity: Application to Luhman 16B
• A Spectroscopic Analysis of a Sample of K2 Planet-Host Stars: Stellar Parameters, Metallicities and Planetary Radii
• Scaling K2 VIII: Short-Period Sub-Neptune Occurrence Rates Peak Around Early-Type M Dwarfs
• TOI-1634 b: an Ultra-Short Period Keystone Planet Sitting Inside the M Dwarf Radius Valley
• Scaling K2. V. Statistical Validation of 60 New Exoplanets From K2 Campaigns 2-18