A New Window into Planet Formation and Migration: Refractory-to-Volatile Elemental Ratios in Ultra-hot Jupiters

Abstract

A primary goal of exoplanet characterization is to use a planet's current composition to understand how that planet formed. For example, the C/O ratio has long been recognized as carrying important information on the chemistry of volatile species. Refractory elements, like Fe, Mg, and Si, are usually not considered in this conversation because they condense into solids like Fe(s) or MgSiO${}_3$ and would be removed from the observable, gaseous atmosphere in exoplanets cooler than about 2000~K. However, planets hotter than about 2000~K, called ultra-hot Jupiters (UHJs), are warm enough to largely avoid the condensation of refractory species. In this paper, we explore the insight that the measurement of refractory abundances can provide into a planet's origins. Through refractory-to-volatile elemental abundance ratios, we can estimate a planet's atmospheric rock-to-ice fraction and constrain planet formation and migration scenarios. We first relate a planet's present-day refractory-to-volatile ratio to its rock-to-ice ratio from formation using various compositional models for the rocky and icy components of the protoplanetary disk. We discuss potential confounding factors like the sequestration of heavy metals in the core and condensation. We then show such a measurement using atmospheric retrievals of the low-resolution UV-IR transmission spectrum of WASP-121b with PETRA, from which we estimate a refractory-to-volatile ratio of 5.0${}_{-2.7}^{+6.0}\times$ solar and a rock-to-ice ratio greater than 2/3. This result is consistent with significant atmospheric enrichment by rocky planetismals. Lastly, we discuss the rich future potential for measuring refractory-to-volatile ratios in ultra-hot Jupiters with the arrival of JWST and by combining observations at low- and high-resolution.

arXiv comment20 pages, 9 Figures. Accepted for publication in ApJ

References in corpus (138)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• The NumPy array: a structure for efficient numerical computation
• Shrinking binary and planetary orbits by Kozai cycles with tidal friction
• Detection of an Extrasolar Planet Atmosphere
• The effects of snowlines on C/O in planetary atmospheres
• A continuum from clear to cloudy hot-Jupiter exoplanets without primordial water depletion
• Planet-disk interaction and orbital evolution
• Atmospheric Escape from Hot Jupiters
• Infrared Transmission Spectroscopy of the Exoplanets HD209458b and XO-1b Using the Wide Field Camera-3 on the Hubble Space Telescope
• C/O ratio as a Dimension for Characterizing Exoplanetary Atmospheres
• The peculiar solar composition and its possible relation to planet formation
• Planetary evaporation by UV & X-ray radiation: basic hydrodynamics
• The Mass-Metallicity Relation for Giant Planets
• A Precise Water Abundance Measurement for the Hot Jupiter WASP-43b
• Detection of Carbon Monoxide and Water Absorption Lines in an Exoplanet Atmosphere
• Comparing Jupiter interior structure models to Juno gravity measurements and the role of a dilute core
• The imprint of exoplanet formation history on observable present-day spectra of hot Jupiters
• Characterizing transiting exoplanet atmospheres with JWST
• A Systematic Retrieval Analysis of Secondary Eclipse Spectra I: A Comparison of Atmospheric Retrieval Techniques
• Dearth of short-period Neptunian exoplanets - a desert in period-mass and period-radius planes
• Structure and evolution of super-Earth to super-Jupiter exoplanets: I. heavy element enrichment in the interior
• From thermal dissociation to condensation in the atmospheres of ultra hot Jupiters: WASP-121b in context
• Metals in the Exosphere of the Highly Irradiated Planet WASP-12b
• Spectrally resolved detection of sodium in the atmosphere of HD189733b with the HARPS spectrograph
• Pebble isolation mass --- scaling law and implications for the formation of super-Earths and gas giants
• Nightside condensation of iron in an ultra-hot giant exoplanet
• The Compositional Diversity of Extrasolar Terrestrial Planets: I. In-Situ Simulations
• H- Opacity and Water Dissociation in the Dayside Atmosphere of the Very Hot Gas Giant WASP-18 b
• HD 209458b in New Light: Evidence of Nitrogen Chemistry, Patchy Clouds and Sub-Solar Water
• Towards Chemical Constraints on Hot Jupiter Migration
• The Two Modes of Gas Giant Planet Formation
• Retrieving Temperatures and Abundances of Exoplanet Atmospheres with High-Resolution Cross-Correlation Spectroscopy
• A new vision on giant planet interiors: the impact of double diffusive convection
• A giant planet undergoing extreme ultraviolet irradiation by its hot massive-star host
• Equilibrium chemistry down to 100 K - Impact of silicates and phyllosilicates on carbon/oxygen ratio
• In Situ Formation and Dynamical Evolution of Hot Jupiter Systems
• Extremely Irradiated Hot Jupiters: Non-Oxide Inversions, H- Opacity, and Thermal Dissociation of Molecules
• Atomic iron and titanium in the atmosphere of the exoplanet KELT-9b
• Photoevaporation and High-Eccentricity Migration Created the Sub-Jovian Desert
• The escape of heavy atoms from the ionosphere of HD209458b. I. A photochemical-dynamical model of the thermosphere
• Planets opening dust gaps in gas disks
• Mass-Metallicity Trends in Transiting Exoplanets from Atmospheric Abundances of H${}_2$O, Na, and K
• A spectral survey of an ultra-hot Jupiter: Detection of metals in the transmission spectrum of KELT-9 b
• Detection of carbon monoxide in the high-resolution day-side spectrum of the exoplanet HD 189733b
• ExoMol line lists XVIII. The high temperature spectrum of VO
• New indication for a dichotomy in the interior structure of Uranus and Neptune from the application of modified shape and rotation data
• Retrieving scattering clouds and disequilibrium chemistry in the atmosphere of HR 8799e
• Tracing the Ingredients for a Habitable Earth from Interstellar Space through Planet Formation
• WASP-121 b: a hot Jupiter in a polar orbit and close to tidal disruption
• HAT-P-26b: A Neptune-Mass Exoplanet with a Well Constrained Heavy Element Abundance
• Detection of Fe I in the atmosphere of the ultra-hot Jupiter WASP-121b, and a new likelihood-based approach for Doppler-resolved spectroscopy
• Heat transport in giant (exo)planets: a new perspective
• HST hot Jupiter Transmission Spectral Survey: A detection of Na and strong optical absorption in HAT-P-1b
• An extended hydrogen envelope of the extremely hot giant exoplanet KELT-9b
• Simultaneous Detection of Water, Methane and Carbon Monoxide in the Atmosphere of Exoplanet HR8799b
• The HST PanCET Program: Exospheric Mg II and Fe II in the Near-UV transmission spectrum of WASP-121b using Jitter Decorrelation
• Atmospheric characterization of the ultra-hot Jupiter MASCARA-2b/KELT-20b
• Carbon monoxide and water vapor in the atmosphere of the non-transiting exoplanet HD 179949 b
• Setting the volatile composition of (exo)planet-building material. Does chemical evolution in disk midplanes matter?
• Molecular abundances and C/O ratios in chemically evolving planet-forming disk midplanes
• Modeling the Formation of Giant Planet Cores I: Evaluating Key Processes
• The Complete transmission spectrum of WASP-39b with a precise water constraint
• Hot Exoplanet Atmospheres Resolved with Transit Spectroscopy (HEARTS) IV. A spectral inventory of atoms and molecules in the high-resolution transmission spectrum of WASP-121 b
• High-Resolution Spectroscopic Detection of TiO and Stratosphere in the Day-side of WASP-33b
• An optical transmission spectrum for the ultra-hot Jupiter WASP-121b measured with the Hubble Space Telescope
• Spectral and atmospheric characterization of 51 Eridani b using VLT/SPHERE
• High temperature condensate clouds in super-hot Jupiter atmospheres
• Carbon Deficiency in Externally-Polluted White Dwarfs: Evidence for Accretion of Asteroids
• A non-grey analytical model for irradiated atmospheres. I: Derivation
• From stellar nebula to planets: the refractory components
• The water abundance in Jupiter's equatorial zone
• Discovery of water at high spectral resolution in the atmosphere of 51 Peg b
• Atmospheric Rossiter-McLaughlin effect and transmission spectroscopy of WASP-121b with ESPRESSO
• Peering into the formation history of beta Pictoris b with VLTI/GRAVITY long baseline interferometry
• Carbon and oxygen abundances in stellar populations
• The Peculiar Atmospheric Chemistry of KELT-9b
• Neutral Iron Emission Lines From The Day-side Of KELT-9b -- The GAPS Programme With HARPS-N At TNG XX
• The In Situ Formation of Giant Planets at Short Orbital Periods
• Hot Exoplanet Atmospheres Resolved with Transit Spectroscopy (HEARTS) - II. A broadened sodium feature on the ultra-hot giant WASP-76b
• Connecting Giant Planet Atmosphere and Interior Modeling: Constraints on Atmospheric Metal Enrichment
• Hubble Space Telescope hot Jupiter Transmission Spectral Survey: detection of water in HAT-P-1b from Wide Field Camera 3 near-infrared spatial scan observations
• A framework to combine low- and high-resolution spectroscopy for the atmospheres of transiting exoplanets
• Jupiter's composition suggests its core assembled exterior to the N2 snowline
• Jupiter's evolution with primordial composition gradients
• Hot Exoplanet Atmospheres Resolved with Transit Spectroscopy (HEARTS) III. Atmospheric structure of the misaligned ultra-hot Jupiter WASP-121b
• VLT FORS2 comparative transmission spectroscopy: Detection of Na in the atmosphere of WASP-39b from the ground
• Methane on Uranus: The case for a compact CH4 cloud layer at low latitudes and a severe CH4 depletion at high-latitudes based on re-analysis of Voyager occultation measurements and STIS spectroscopy
• Metal enrichment leads to low atmospheric C/O ratios in transiting giant exoplanets
• The Elemental Abundances (with Uncertainties) of the Most Earth-like Planet
• Atmospheric dynamics and the variable transit of KELT-9 b
• Determination of the minimum masses of heavy elements in the envelopes of Jupiter and Saturn
• Making the Earth: Combining Dynamics and Chemistry in the Solar System
• On degeneracies in retrievals of exoplanetary transmission spectra
• Mass loss rate and local thermodynamic state of KELT-9 b thermosphere from the hydrogen Balmer series
• On the formation of terrestrial planets in hot-Jupiter systems
• Detection of neutral atomic species in the ultra-hot jupiter WASP-121b
• From planetesimals to planets: volatile molecules
• Exoplanet atmospheres with GIANO II. Detection of molecular absorption in the dayside spectrum of HD 102195b
• On the origin of the sub-Jovian desert in the orbital-period--planetary-mass plane
• Na I and H$\alpha$ absorption features in the atmosphere of MASCARA-2b/KELT-20b
• Searching for Thermal Inversion Agents in the Transmission Spectrum of MASCARA-2b/KELT-20b: Detection of Neutral Iron and Ionised Calcium H$\&$K Lines
• An emission spectrum for WASP-121b measured across the 0.8-1.1 micron wavelength range using the Hubble Space Telescope
• Non-detection of TiO and VO in the atmosphere of WASP-121b using high-resolution spectroscopy
• Planetesimal Compositions in Exoplanet Systems
• An Ultra-Hot Neptune in the Neptune desert
• Gas composition of main volatile elements in protoplanetary discs and its implication for planet formation
• From stellar nebula to planetesimals
• Stellar clustering shapes the architectures of planetary systems
• The Evolution and Internal Structure of Jupiter and Saturn with Compositional Gradients
• The Solar Nebula on Fire: A Solution to the Carbon Deficit in the Inner Solar System
• A temperature inversion with atomic iron in the ultra-hot dayside atmosphere of WASP-189b
• Beyond the Iron Peak: r- and s-process Elemental Abundances in Stars with Planets
• Convection and Mixing in Giant Planet Evolution
• Destruction of Refractory Carbon in Protoplanetary Disks
• The composition and size distribution of the dust in the coma of comet Hale-Bopp
• GPI spectra of HR 8799 c, d, and e from 1.5 to 2.4$\mu$m with KLIP Forward Modeling
• Detection of Fe\,{\sc i} Emission in the Day-side Spectrum of WASP-33b
• Connecting planet formation and astrochemistry: Refractory carbon depletion leading to super-stellar C/O in giant planetary atmospheres
• Jupiter formed as a pebble pile around the N${}_2$ ice line
• Combining low- to high-resolution transit spectroscopy of HD 189733b. Linking the troposphere and the thermosphere of a hot gas giant
• Double-diffusive erosion of the core of Jupiter
• Fingerprints of giant planets in the composition of solar twins
• On the origin of elemental abundances in the terrestrial planets
• Jupiter's heavy-element enrichment expected from formation models
• Neutral Cr and V in the atmosphere of ultra hot jupiter WASP-121 b
• WASP-127b transmission spectrum]{Abundance measurements of H${}_2$O and carbon-bearing species in the atmosphere of WASP-127b confirm its super-solar metallicity
• Comet formation in collapsing pebble clouds. What cometary bulk density implies for the cloud mass and dust-to-ice ratio
• Do Metal-Rich Stars Make Metal-Rich Planets? New Insights on Giant Planet Formation from Host Star Abundances
• Interpreting High-Resolution Spectroscopy of Exoplanets Using Cross-Correlations and Supervised Machine Learning
• The composition of hot Jupiter atmospheres assembled within chemically evolved protoplanetary discs
• Gemini/GMOS Optical Transmission Spectroscopy of WASP-121b: signs of variability in an ultra-hot Jupiter?
• UV Exoplanet Transmission Spectral Features as Probes of Metals and Rainout
• The hot Jupiter period-mass distribution as a signature of in situ formation
• Diagnosing aerosols in extrasolar giant planets with cross-correlation function of water bands
• Destruction of refractory carbon grains drives the final stage of proto-planetary disk chemistry
• Suppressed Far-UV Stellar Activity and Low Planetary Mass Loss in the WASP-18 System
• The PHOENIX Exoplanet Retrieval Algorithm and Using H${}^{-}$ Opacity as a Probe in Ultra-hot Jupiters
• Warm dust surface chemistry in protoplanetary disks. Formation of phyllosilicates

Cited by in corpus (62)

• Early Release Science of the exoplanet WASP-39b with JWST NIRISS
• Early Release Science of the exoplanet WASP-39b with JWST NIRCam
• Identification of carbon dioxide in an exoplanet atmosphere
• Where is the Water? Jupiter-like C/H ratio but strong H${}_2$O depletion found on $\tau$ Boötis b using SPIRou
• Five key exoplanet questions answered via the analysis of 25 hot Jupiter atmospheres in eclipse
• Vanadium oxide and a sharp onset of cold-trapping on a giant exoplanet
• How drifting and evaporating pebbles shape giant planets II: Volatiles and refractories in atmospheres
• Chemical Diversity in Protoplanetary Disks and Its Impact on the Formation History of Giant Planets
• Relative abundance constraints from high-resolution optical transmission spectroscopy of WASP-121b, and a fast model-filtering technique for accelerating retrievals
• Breaking Degeneracies in Formation Histories by Measuring Refractory Content in Gas Giants
• Retrieval survey of metals in six ultra-hot Jupiters: Trends in chemistry, rain-out, ionisation and atmospheric dynamics
• Carbon monoxide emission lines reveal an inverted atmosphere in the ultra hot Jupiter WASP-33 b consistent with an eastward hot spot
• Spatially-resolving the terminator: Variation of Fe, temperature and winds in WASP-76 b across planetary limbs and orbital phase
• Close-in ice lines and the super-stellar C/O ratio in discs around very low-mass stars
• The GAPS Programme at TNG. XLI. The climate of KELT-9b revealed with a new approach to high spectral resolution phase curves
• Volatile-to-sulfur Ratios Can Recover a Gas Giant's Accretion History
• Evidence that the Hot Jupiter WASP-77 A b Formed Beyond Its Parent Protoplanetary Disk's H2O Ice Line
• High-resolution atmospheric retrievals of WASP-121b transmission spectroscopy with ESPRESSO: Consistent relative abundance constraints across multiple epochs and instruments
• A JWST NIRSpec Phase Curve for WASP-121b: Dayside Emission Strongest Eastward of the Substellar Point and Nightside Conditions Conducive to Cloud Formation
• Mining the Ultra-Hot Skies of HAT-P-70b: Detection of a Profusion of Neutral and Ionized Species
• CRIRES+ and ESPRESSO reveal an atmosphere enriched in volatiles relative to refractories on the ultra-hot Jupiter WASP-121b
• TESS Giants Transiting Giants II: The hottest Jupiters orbiting evolved stars
• Keck/KPIC Emission Spectroscopy of WASP-33b
• The ESO SupJup Survey I: Chemical and isotopic characterisation of the late L-dwarf DENIS J0255-4700 with CRIRES${}^{+}$
• 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
• The ESO SupJup Survey III: Confirmation of 13CO in YSES 1 b and Atmospheric Detection of YSES 1 c with CRIRES+
• Unifying High- and Low-resolution Observations to Constrain the Dayside Atmosphere of KELT-20b/MASCARA-2b
• Solar-to-supersolar sodium and oxygen absolute abundances for a "hot Saturn" orbiting a metal-rich star
• Measuring Elemental Abundances of JWST Target Stars for Exoplanet Characterization I. FGK Stars
• Constraining the origin of giant exoplanets via elemental abundance measurements
• A sub-solar metallicity on the ultra-short period planet HIP 65Ab
• On spectroscopic phase-curve retrievals: H2 dissociation and thermal inversion in the atmosphere of the ultra-hot Jupiter WASP-103 b
• Revising the Giant Planet Mass-Metallicity Relation: Deciphering the Formation Sequence of Giant Planets
• Elemental Abundances of the Super-Neptune WASP-107b's Host Star Using High-resolution, Near-infrared Spectroscopy
• High-resolution atmospheric retrievals of WASP-76b transmission spectroscopy with ESPRESSO: Monitoring limb asymmetries across multiple transits
• Measuring Tracers of Planet Formation in the Atmosphere of WASP-77A b: Sub-stellar O/H and C/H ratios, with a stellar C/O ratio and a potentially Super-stellar Ti/H ratio
• Time Resolved Absorption of Six Chemical Species With MAROON-X Points to Strong Drag in the Ultra Hot Jupiter TOI-1518 b
• Why is it So Hot in Here? Exploring Population Trends in $\text{Spitzer}$ Thermal Emission Observations of Hot Jupiters using Planet-Specific Self-Consistent Atmospheric Models
• Atmospheric characterization of the super-Jupiter HIP 99770 b with KPIC
• WASP-121b's transmission spectrum observed with JWST/NIRSpec G395H reveals thermal dissociation and SiO in the atmosphere
• The compositions of the HR 8799 planets reflect accretion of both solids and metal-enriched gas
• Detection of Na and K in the atmosphere of the hot Jupiter HAT-P-1b with P200/DBSP
• Refractory and Volatile Species in the UV-to-IR Transmission Spectrum of Ultra-hot Jupiter WASP-178b with HST and JWST
• New perspectives on MASCARA-1b: A combined analysis of pre- and post-eclipse emission data using CRIRES+
• Strong NUV Refractory Absorption and Dissociated Water in the Hubble Transmission Spectrum of the Ultra Hot Jupiter KELT-20 b
• Evidence of Titanate Clouds in the Day-side Atmosphere of the Ultra-Hot Jupiter WASP-121b
• Simultaneous multicolour transit photometry of hot Jupiters HAT-P-19b, HAT-P-51b, HAT-P-55b, and HAT-P-65b
• Atmospheric Mass Loss from TOI-1259 A b, a Gas Giant Planet With a White Dwarf Companion
• Secrets in the shadow: High precision stellar abundances of fast-rotating A-type exoplanet host stars through transit spectroscopy
• A re-analysis of equilibrium chemistry in five hot Jupiters
• The planetary-mass-limit VLT/SINFONI library: Spectral extraction and atmospheric characterization via forward modeling
• A Comprehensive Analysis of the Panchromatic Transmission Spectrum of the Hot-Saturn WASP-96 b: Nondetection of Haze, Possible Sodium Limb Asymmetry, Stellar Characterization, and Formation History
• Detection of Na in the atmosphere of the hot Jupiter HAT-P-55b
• The Missing Link: Testing Galactic Chemical Evolution Models with the First Multi-Isotopic Abundances in Solar Twin Stars
• Spitzer phase curve observations and circulation models of the inflated ultra-hot Jupiter WASP-76b
• Interpreting the atmospheric composition of exoplanets: sensitivity to planet formation assumptions
• The Wanderer: Charting WASP-77A b's Formation and Migration Using a System-Wide Inventory of Carbon and Oxygen Abundances
• First Results from WINERED: Detection of Emission Lines from Neutral Iron and a Combined Set of Trace Species on the Dayside of WASP-189 b
• Assessing robustness and bias in 1D retrievals of 3D Global Circulation Models at high spectral resolution: a WASP-76 b simulation case study in emission
• Revisiting the atmosphere of HAT-P-70b with CARMENES high-resolution transmission spectroscopy
• Direct Images of CO2 Absorption in the Atmosphere of a Super-Jupiter: Enhanced Metallicity Suggestive of Formation in a Disk
• The breaking of cold traps and onset of titanium in ultra-hot Jupiter atmospheres: WASP-189b in context