Super stellar abundances of alkali metals suggest significant migration for Hot Jupiters

Abstract

We investigate the origin of the measured over-abundance of alkali metals in the atmospheres of hot gas giants, relative to both their host stars and their atmospheric water abundances. We show that formation exterior to the water snow line followed by inward disc-driven migration results in excess accretion of oxygen-poor, refractory-rich material from within the snow-line. This naturally leads to enrichment of alkali metals in the planetary atmosphere relative to the bulk composition of its host star but relative abundances of water that are similar to the stellar host. These relative abundances cannot be explained by in situ formation which places the refractory elements in the planetary deep interior rather than the atmosphere. We therefore suggest that the measured compositions of the atmospheres of hot Jupiters are consistent with significant migration for at least a subset of hot gas giants. Our model makes robust predictions about atmospheric composition that can be confirmed with future data from JWST and Ariel.

arXiv comment10 pages, 5 figures, 1 table, accepted for publication in MNRAS

References in corpus (52)

• The PLATO 2.0 Mission
• The effects of snowlines on C/O in planetary atmospheres
• Accretion Disks around Young Objects. I. The Detailed Vertical Structure
• On the width and shape of gaps in protoplanetary disks
• Origins of Hot Jupiters
• The Mass-Metallicity Relation for Giant Planets
• The imprint of exoplanet formation history on observable present-day spectra of hot Jupiters
• Characterizing transiting exoplanet atmospheres with JWST
• Measurement of Spin-Orbit Alignment in an Extrasolar Planetary System
• Atmospheres of protoplanetary cores: critical mass for nucleated instability
• Models of Jupiter's Growth Incorporating Thermal and Hydrodynamic Constraints
• Initial Conditions of Planet Formation: Lifetimes of Primordial Disks
• Towards Chemical Constraints on Hot Jupiter Migration
• In Situ Formation and Dynamical Evolution of Hot Jupiter Systems
• Mass-Metallicity Trends in Transiting Exoplanets from Atmospheric Abundances of H${}_2$O, Na, and K
• H${}_2$O abundances and cloud properties in ten hot giant exoplanets
• Overstable Librations can account for the Paucity of Mean Motion Resonances among Exoplanet Pairs
• A consistent retrieval analysis of 10 Hot Jupiters observed in transmission
• Detection of titanium oxide in the atmosphere of a hot Jupiter
• Migration of massive planets in accreting disks
• Mars' Growth Stunted by an Early Giant Planet Instability
• An absolute sodium abundance for a cloud-free 'hot Saturn' exoplanet
• H2O abundances in the atmospheres of three hot Jupiters
• Transit spectroscopy with JWST: Systematics, starspots and stitching
• Jupiter's evolution with primordial composition gradients
• Giant Planet Formation, Evolution, and Internal Structure
• On the orbit of the short-period exoplanet WASP-19b
• Metal enrichment leads to low atmospheric C/O ratios in transiting giant exoplanets
• The Rotation Period of the Planet-Hosting Star HD 189733
• Transit Signatures of Inhomogeneous Clouds on Hot Jupiters: Insights From Microphysical Cloud Modeling
• The GTC exoplanet transit spectroscopy survey IX. Detection of Haze, Na, K, and Li in the super-Neptune WASP-127b
• The Challenge of Forming a Fuzzy Core in Jupiter
• On the evolution of mean motion resonances through stochastic forcing: Fast and slow libration modes and the origin of HD128311
• Planet-Disc Interactions and Early Evolution of Planetary Systems
• The origin of the high metallicity of close-in giant exoplanets: Combined effect of the resonant and aerodynamic shepherding
• Toward a new paradigm for Type II migration
• C/O and O/H Ratios Suggest Some Hot Jupiters Originate Beyond the Snow Line
• A photometric study of the hot exoplanet WASP-19b
• Is there NaI in the atmosphere of HD 209458b? Effect of the centre-to-limb variation and Rossiter-McLaughlin effect in transmission spectroscopy studies
• WASP-127b: A misaligned planet with a partly cloudy atmosphere and tenuous sodium signature seen by ESPRESSO
• External Photoevaporation of the Solar Nebula: Jupiter's Noble Gas Enrichments
• The formation of systems with closely spaced low-mass planets and the application to Kepler-36
• Jupiter's heavy-element enrichment expected from formation models
• The Volatility Trend of Protosolar and Terrestrial Elemental Abundances
• The fate of planetesimal discs in young open clusters: implications for 1I/'Oumuamua, the Kuiper belt, the Oort cloud and more
• Understanding the assembly of Kepler's compact planetary systems
• The distribution of heavy-elements in giant protoplanetary atmospheres: the importance of planetesimal-envelope interactions
• Ariel Planetary Interiors White Paper
• Planetary Migration in Protoplanetary Disks
• Breaking mean-motion resonances during Type I planet migration
• There might be giants: unseen Jupiter-mass planets as sculptors of tightly-packed planetary systems
• Atmospheric Characterization via Broadband Color Filters on the PLAnetary Transits and Oscillations of stars (PLATO) Mission

Cited by in corpus (10)

• Early Release Science of the exoplanet WASP-39b with JWST NIRISS
• Breaking Degeneracies in Formation Histories by Measuring Refractory Content in Gas Giants
• Close-in ice lines and the super-stellar C/O ratio in discs around very low-mass stars
• How drifting and evaporating pebbles shape giant planets III: The formation of WASP-77A b and $\tau$ Boötis b
• Nitrogen as a Tracer of Giant Planet Formation. I.: A Universal Deep Adiabatic Profile and Semi-analytical Predictions of Disequilibrium Ammonia Abundances in Warm Exoplanetary Atmospheres
• Constraining the origin of giant exoplanets via elemental abundance measurements
• Convective Mixing in Gas Giant Planets with Primordial Composition Gradients
• Inferring Late Stage Enrichment of Exoplanet Atmospheres from Observed Interstellar Comets
• The Missing Link: Testing Galactic Chemical Evolution Models with the First Multi-Isotopic Abundances in Solar Twin Stars
• The Wanderer: Charting WASP-77A b's Formation and Migration Using a System-Wide Inventory of Carbon and Oxygen Abundances