Galactic chemical evolution of exoplanet host stars: Are high-mass planetary systems young?

Abstract

The imprints of stellar nucleosynthesis and chemical evolution of the galaxy can be seen in different stellar populations, with older generation stars showing higher $\alpha$-element abundances while the later generations becoming enriched with iron-peak elements. The evolutionary connections and chemical characteristics of circumstellar disks, stars, and their planetary companions can be inferred by studying the interdependence of planetary and host star properties. Numerous studies in the past have confirmed that high-mass giant planets are commonly found around metal-rich stars, while the stellar hosts of low-mass planets have a wide range of metallicity. In this work, we analyzed the detailed chemical abundances for a sample of $>900$ exoplanet hosting stars drawn from different radial velocity and transit surveys. We correlate the stellar abundance trends for $\alpha$ and iron-peak elements with the planets' mass. We find the planet mass-abundance correlation to be primarily negative for $\alpha$-elements and marginally positive or zero for the iron-peak elements, indicating that stars hosting giant planets are relatively younger. This is further validated by the age of the host stars obtained from isochrone fitting. The later enrichment of protoplanetary material with iron and iron-peak elements is also consistent with the formation of the giant planets via the core accretion process. A higher metal fraction in the protoplanetary disk is conducive to rapid core growth, thus providing a plausible route for the formation of giant planets. This study, therefore, indicates the observed trends in stellar abundances and planet mass are most likely a natural consequence of Galactic chemical evolution.

arXiv commentThe Astronomical Journal

References in corpus (87)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• Array Programming with NumPy
• Astropy: A Community Python Package for Astronomy
• PARSEC: stellar tracks and isochrones with the PAdova and TRieste Stellar Evolution Code
• The Dartmouth Stellar Evolution Database
• Characteristics of planetary candidates observed by Kepler, II: Analysis of the first four months of data
• Spectroscopic [Fe/H] for 98 extra-solar planet-host stars: Exploring the probability of planet formation
• Neutron capture in low mass Asymptotic Giant Branch stars: cross sections and abundance signatures
• Galactic chemical evolution: Carbon through Zinc
• The NASA Exoplanet Archive: Data and Tools for Exoplanet Research
• Light Curves of the Neutron Star Merger GW170817/SSS17a: Implications for R-Process Nucleosynthesis
• Origin of the Heaviest Elements: the Rapid Neutron-Capture Process
• Giant Planet Occurrence in the Stellar Mass-Metallicity Plane
• Models of Giant Planet formation with migration and disc evolution
• The Dawes Review 2: Nucleosynthesis and stellar yields of low and intermediate-mass single stars
• Probabilistic Forecasting of the Masses and Radii of Other Worlds
• Chemical abundances of 1111 FGK stars from the HARPS GTO planet search program.Galactic stellar populations and planets
• The age structure of stellar populations in the solar vicinity. Clues of a two-phase formation history of the Milky Way disk
• Determining stellar atmospheric parameters and chemical abundances of FGK stars with iSpec
• The metal-rich nature of stars with planets
• The California Planet Survey I. Four New Giant Exoplanets
• Spectroscopy Made Easy: Evolution
• The California-Kepler Survey. IV. Metal-rich Stars Host a Greater Diversity of Planets
• Spectral Properties of Cool Stars: Extended Abundance Analysis of 1617 Planet Search Stars
• Three regimes of extrasolar planets inferred from host star metallicities
• On the Role of Disks in the Formation of Stellar Systems: A Numerical Parameter Study of Rapid Accretion
• The California-Kepler Survey. I. High Resolution Spectroscopy of 1305 Stars Hosting Kepler Transiting Planets
• Modern stellar spectroscopy caveats
• Nucleosynthesis in Type Ia Supernovae
• Dust Evolution and the Formation of Planetesimals
• Formation of giant planets by fragmentation of protoplanetary disks
• Stellar Abundances in the Solar Neighborhood: The Hypatia Catalog
• High-precision abundances of elements in solar twin stars: Trends with stellar age and elemental condensation temperature
• The Origin of r-Process Elements in the Milky Way
• Accurate parameters of 93 solar-type Kepler targets
• The Mass of the Convective Zone in FGK Main Sequence Stars and the Effect of Accreted Planetary Material on Apparent Metallicity Determinations
• Chemical abundances of 1111 FGK stars from the HARPS GTO planet search program II: Cu, Zn, Sr, Y, Zr, Ba, Ce, Nd and Eu
• Reconstructing the star formation history of the Milky Way disc(s) from chemical abundances
• A new alpha-enhanced super-solar metallicity population
• From Nuclei to the Cosmos: Tracing Heavy-Element Production with the Oldest Stars
• The Chemical Homogeneity of Sun-like Stars in the Solar Neighborhood
• The California-Kepler Survey. II. Precise Physical Properties of 2025 Kepler Planets and Their Host Stars
• The origin and evolution of r- and s-process elements in the Milky Way stellar disk
• The New Generation Planetary Population Synthesis (NGPPS). II. Planetary population of solar-like stars and overview of statistical results
• Abundance to age ratios in the HARPS-GTO sample with Gaia DR2: Chemical clocks for a range of [Fe/H]
• The GALAH survey: An abundance, age, and kinematic inventory of the solar neighbourhood made with TGAS
• Overabundance of alpha-elements in exoplanet host stars
• The Effect of Different Type Ia Supernova Progenitors on Galactic Chemical Evolution
• Hot Jupiters are Destroyed by Tides While Their Host Stars are on the Main Sequence
• C, S, Zn and Cu abundances in planet-harbouring stars
• Galactic chemical abundance evolution in the solar neighborhood up to the Iron peak
• On the formation time scale and core masses of gas giant planets
• Oxygen abundances in G- and F-type stars from HARPS
• Silicon and Oxygen Abundances in Planet-Host Stars
• Spectroscopy of Faint Kepler Mission Exoplanet Candidate Host Stars
• The California Planet Survey III. A Possible 2:1 Resonance in the Exoplanetary Triple System HD 37124
• On the Metallicities of Kepler Stars
• Possible Stellar Metallicity Enhancements from the Accretion of Planets
• Planetary Formation Scenarios Revistied: Core-Accretion Versus Disk Instability
• Dissecting stellar chemical abundance space with t-SNE
• The HARPS search for southern extrasolar planets XXV. Results from the metal-poor sample
• Heavy metal rules. I. Exoplanet incidence and metallicity
• Age-resolved chemistry of red giants in the solar neighbourhood
• Stellar Pollution in the Solar Neighborhood
• The growth and hydrodynamic collapse of a protoplanet envelope
• Metallicity-Dependent Signatures in the Kepler Planets
• Properties and occurrence rates of $Kepler$ exoplanet candidates as a function of host star metallicity from the DR25 catalog
• Planet Formation Theory in the Era of ALMA and Kepler: from Pebbles to Exoplanets
• Spectral Properties of Cool Stars: Extended Abundance Analysis of Kepler Objects of Interest
• Chemical abundances of 1111 FGK stars from the HARPS GTO planet search program IV. Carbon and C/O ratios for Galactic stellar populations and planet hosts
• The AMBRE project: Iron-peak elements in the solar neighbourhood
• CNO behaviour in planet-harbouring stars. II. Carbon abundances in stars with and without planets using the CH band
• Evidence for $\gtrsim 4$ Gyr timescales of neutron star mergers from Galactic archaeology
• Host star metallicity of directly imaged wide-orbit planets: implications for planet formation
• The Most Metal-poor Stars in the Magellanic Clouds are $r$-process Enhanced
• Chemical abundances of 1111 FGK stars from the HARPS-GTO planet search sample. III. Sulfur
• The Mass Distribution Function of Planets
• Spectroscopic study of CEMP-(s & r/s) stars- Revisiting classification criteria and formation scenarios, highlighting i-process nucleosynthesis
• CNO behaviour in planet-harbouring stars. I Nitrogen abundances in stars with planets
• The California Planet Survey II. A Saturn-Mass Planet Orbiting the M Dwarf Gl649
• The APOGEE Spectroscopic Survey of Kepler Planet Hosts: Feasibility, Efficiency, and First Results
• Chemical Composition Of Bright Stars In The Northern Hemisphere: Star-Planet Connection
• The Influence of 10 Unique Chemical Elements in Shaping the Distribution of Kepler Planets
• Chemical abundances of neutron capture elements in exoplanet-hosting stars
• A statistical search for Star-Planet Interaction in the UltraViolet using GALEX
• The peculiar abundances of HE 1005-1439. A carbon-enhanced extremely metal-poor star contaminated with products of both s-and i-process nucleosynthesis
• Semi-analytic modelling of the europium production by neutron star mergers in the halo of the Milky Way

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• Planet formation throughout the Milky Way: Planet populations in the context of Galactic chemical evolution
• Age distribution of exoplanet host stars: Chemical and Kinematics age proxies from GAIA DR3
• The chemical evolution of the solar neighbourhood for planet-hosting stars
• Carbon abundance of stars in the LAMOST-Kepler field
• Populating The Milky Way: Characterising Planet Demographics by Combining Galaxy Formation Simulations and Planet Population Synthesis Models
• Ariel stellar characterisation III. Fast rotators and new FGK stars in the Ariel Mission Candidate Sample
• The peculiar composition of the Sun is not related to giant planets
• Where in the Milky Way Do Exoplanets Preferentially Form?
• The Missing Link: Testing Galactic Chemical Evolution Models with the First Multi-Isotopic Abundances in Solar Twin Stars
• Chemical composition of planetary hosts: II. Abundances of neutron-capture elements
• MAUVE: An Ultraviolet Astrophysics Probe Mission Concept