A High-Resolution Spectroscopic Survey of Directly Imaged Companion Hosts: II. Diversity in C/O Ratios among Host Stars

Abstract

The era of JWST has enabled measurements of abundances of elements such as C, O, and even Na, S, K, and Fe in planetary atmospheres to very high precisions ($\sim$0.1 dex). Accurate inference of planet formation using these elemental abundances require the corresponding abundance measurements for the host star. We present the second set of results from our high-resolution spectroscopic survey of directly imaged companion host stars, measuring abundances of 16 elements (including C, O, Na, Mg, Si, S, K and Fe) for five directly imaged companion host stars. Using both the spectral fitting and the equivalent width methods, we find solar C/O ratios for HR 2562 (0.58 $\pm$ 0.09), AB Pic (0.50 $\pm$ 0.14), and YSES 1 (0.45 $\pm$ 0.05), and sub-solar C/O ratios for PZ Tel (0.28 $\pm$ 0.05) and $\beta$ Pic (0.22 $\pm$ 0.06). The $4\sigma$ sub-solar C/O detections for PZ Tel and $\beta$ Pic highlight the importance of accurate stellar C/O estimates for constraining planet formation. Subsequently, we combine our abundances with those from our previous work to measure population-level average elemental abundances. We find super-solar carbon and oxygen for this stellar population, indicating that the protoplanetary disks around these stars were potentially rich in volatiles. We compare stellar C/O to those of their companions, revealing super-stellar C/O for several objects that suggest planet-like formation mechanisms. We also compare the C/O of our directly imaged companion host star population with other planet host stars using the Kolmogorov-Smirnov Test, which indicates insufficient evidence to differentiate between the various stellar populations

37 pages, 22 figures, 9 tables

References in corpus (64)

• Array Programming with NumPy
• The Astropy Project: Sustaining and Growing a Community-oriented Open-source Project and the Latest Major Release (v5.0) of the Core Package
• A grid of MARCS model atmospheres for late-type stars I. Methods and general properties
• New constraints on the chemical evolution of the solar neighbourhood and Galactic disc(s). Improved astrophysical parameters for the Geneva-Copenhagen Survey
• APOGEE Data and Spectral Analysis from SDSS Data Release 16: Seven Years of Observations Including First Results from APOGEE-South
• The Gemini Planet Imager Exoplanet Survey: Giant Planet and Brown Dwarf Demographics From 10-100 AU
• Separating gas-giant and ice-giant planets by halting pebble accretion
• Detection of Carbon Monoxide and Water Absorption Lines in an Exoplanet Atmosphere
• The imprint of exoplanet formation history on observable present-day spectra of hot Jupiters
• The Hipparcos-Gaia Catalog of Accelerations: Gaia EDR3 Edition
• Stellar Abundances in the Solar Neighborhood: The Hypatia Catalog
• The SPHERE infrared survey for exoplanets (SHINE). III. The demographics of young giant exoplanets below 300 au with SPHERE
• Methane, Carbon Monoxide, and Ammonia in Brown Dwarfs and Self-Luminous Giant Planets
• Retrieving scattering clouds and disequilibrium chemistry in the atmosphere of HR 8799e
• Stellar Parameters and Metallicities of Stars Hosting Jovian and Neptunian Mass Planets: A Possible Dependence of Planetary Mass on Metallicity
• Tracing the formation history of giant planets in protoplanetary disks with Carbon, Oxygen, Nitrogen and Sulphur
• Setting the volatile composition of (exo)planet-building material. Does chemical evolution in disk midplanes matter?
• How drifting and evaporating pebbles shape giant planets I: Heavy element content and atmospheric C/O
• Peering into the formation history of beta Pictoris b with VLTI/GRAVITY long baseline interferometry
• The International Deep Planet Survey II: The frequency of directly imaged giant exoplanets with stellar mass
• The 13O-rich atmosphere of a young accreting super-Jupiter
• All-sky Co-moving Recovery Of Nearby Young Members. (ACRONYM) II: The Beta Pictoris Moving Group
• Silicon and Nickel Enrichment in Planet-Host Stars: Observations and Implications for the Core-Accretion Theory of Planet Formation
• 3-D selection of 167 sub-stellar companions to nearby stars
• Critical core mass for enriched envelopes: the role of H2O condensation
• Oxygen abundances in G- and F-type stars from HARPS
• The Orbit and Transit Prospects for $\beta$ Pictoris b constrained with One Milliarcsecond Astrometry
• C/O Ratios of Stars with Transiting Hot Jupiter Exoplanets
• 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
• From stellar nebula to planetesimals
• Two Directly Imaged, Wide-orbit Giant Planets around the Young, Solar Analog TYC 8998-760-1
• Direct discovery of the inner exoplanet in the HD206893 system. Evidence for deuterium burning in a planetary-mass companion
• Discovery of a Substellar Companion to the Nearby Debris Disk Host HR 2562
• Assessment of [Fe/H] determinations for FGK stars in spectroscopic surveys
• The Role of Ice Compositions for Snowlines and the C/N/O Ratios in Active Disks
• Deep exploration of the planets HR 8799 b, c, and d with moderate resolution spectroscopy
• A medium-resolution spectrum of the exoplanet HIP 65426 b
• The Young Suns Exoplanet Survey: Detection of a wide orbit planetary mass companion to a solar-type Sco-Cen member
• Assessing the C/O Ratio Formation Diagnostic: A Potential Trend with Companion Mass
• Volatile-to-sulfur Ratios Can Recover a Gas Giant's Accretion History
• CNO behaviour in planet-harbouring stars. II. Carbon abundances in stars with and without planets using the CH band
• The Second Discovery from the COol Companions ON Ultrawide orbiTS (COCONUTS) Program: A Cold Wide-Orbit Exoplanet around a Young Field M Dwarf at 10.9 pc
• Host star metallicity of directly imaged wide-orbit planets: implications for planet formation
• Peering into the Young Planetary System AB Pic. Atmosphere, Orbit, Obliquity & Second Planetary Candidate
• Characterization of Population III Stars with Stellar Atmosphere and Evolutionary Modeling and Predictions of their Observability with the James Webb Space Telescope
• Orbital and dynamical analysis of the system around HR 8799. New astrometric epochs from VLT/SPHERE and LBT/LUCI
• The ESO SupJup Survey III: Confirmation of 13CO in YSES 1 b and Atmospheric Detection of YSES 1 c with CRIRES+
• Retrieval study of cool, directly imaged exoplanet 51 Eri b
• Moderate-Resolution $K$-Band Spectroscopy of Substellar Companion $\kappa$ Andromedae b
• Probing the impact of varied migration and gas accretion rates for the formation of giant planets in the pebble accretion scenario
• Limits on the Mass and Initial Entropy of 51 Eri b from Gaia EDR3 Astrometry
• Silicate clouds and a circumplanetary disk in the YSES-1 exoplanet system
• Chemical analysis of early-type stars with planets
• An updated visual orbit of the directly-imaged exoplanet 51 Eridani b and prospects for a dynamical mass measurement with Gaia
• New Generation Stellar Spectral Libraries in the Optical and Near-Infrared I: The Recalibrated UVES-POP Library for Stellar Population Synthesis
• Fresh view of the hot brown dwarf HD 984 B through high-resolution spectroscopy
• RVSPY -- Radial Velocity Survey for Planets around Young Stars. Target characterization and high-cadence survey
• Dynamical Mass of the Young Brown Dwarf Companion PZ Tel B
• First spectroscopic observations of the sub-stellar companion of the young debris disk star PZ Telescopii
• The FEROS--Lick/SDSS observational database of spectral indices of FGK stars for stellar population studies
• A High-Resolution Spectroscopic Survey of Directly Imaged Companion Hosts: I. Determination of diagnostic stellar abundances for planet formation and composition
• Direct Spectroscopy of 51 Eridani b with JWST NIRSpec
• Measuring the Stellar and Planetary Properties of the 51 Eridani System

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