Imaging detection of the inner dust belt and the four exoplanets in the HR8799 system with JWST's MIRI coronagraph

Abstract

The multi planet system HR8799 is the first target observed with MIRI's coronagraphs as part of the MIRI-EC Guaranteed Time Observations exoplanets programme in Nov. 2022. We obtained deep observations in three coronagraphic filters from 10 to 15mic (F1065C, F1140C, F1550C), and one standard imaging filter at 20 mic (F2100W), with the goal to extract the photometry of the four planets, as well as to detect and investigate the distribution of circumstellar dust. Using dedicated observations of a reference star, we tested several algorithms to subtract the stellar diffraction pattern while preserving the fluxes of planets, which can be significantly affected by over-subtraction. Measuring correctly the planet's flux values requires accounting for the attenuation by the coronagraphs as a function of their position, and to estimate the normalisation with respect to the central star. We tested several procedures to derive averaged photometric values and error bars. These observations have enabled us to obtain two main results. First of all, the four planets in the system are well recovered, and their mid-IR fluxes, combined with near-IR flux values from the literature, are compared to two exoplanet atmosphere models, ATMO and Exo-REM. As a main outcome, the MIRI photometric data points imply larger radii (0.86 or 1.07 RJ for planet b) and cooler temperatures (950 or 1100 K for planet b), especially for planet b, in better agreement with evolutionary models. Second of all, these JWST/MIRI coronagraphic data also deliver the first spatially resolved detection of the inner warm debris disk, the radius of which is constrained to about 15 au, with flux densities comparable, but lower than former unresolved spectroscopic measurements with Spitzer. abridged...

arXiv commentsubmitted on Sep; 8th, 2023

References in corpus (52)

• The chemical composition of the Sun
• Direct Imaging of Multiple Planets Orbiting the Star HR 8799
• The effects of snowlines on C/O in planetary atmospheres
• Images of a fourth planet orbiting HR 8799
• Spectral Energy Distributions of Hard X-ray selected AGNs in the XMDS Survey
• Detection and Characterization of Exoplanets and Disks using Projections on Karhunen-Loeve Eigenimages
• VOSA: Virtual Observatory SED Analyzer. An application to the Collinder 69 open cluster
• The James Webb Space Telescope Mission
• A new algorithm for point spread function subtraction in high-contrast imaging: a demonstration with angular differential imaging
• The Gemini Planet Imager Exoplanet Survey: Giant Planet and Brown Dwarf Demographics From 10-100 AU
• The Science Performance of JWST as Characterized in Commissioning
• Detection of Carbon Monoxide and Water Absorption Lines in an Exoplanet Atmosphere
• L and T Dwarf Models and the L to T Transition
• Clouds and Chemistry in the Atmosphere of Extrasolar Planet HR8799b
• A new set of atmosphere and evolution models for cool T-Y brown dwarfs and giant exoplanets
• A Combined Subaru/VLT/MMT 1--5 Micron Study of Planets Orbiting HR 8799: Implications for Atmospheric Properties, Masses, and Formation
• Spitzer IRS Spectroscopy of IRAS-Discovered Debris Disks
• The Debris Disk Around HR 8799
• The Mid-Infrared Instrument for JWST, II: Design and Build
• The SPHERE infrared survey for exoplanets (SHINE). III. The demographics of young giant exoplanets below 300 au with SPHERE
• Retrieving scattering clouds and disequilibrium chemistry in the atmosphere of HR 8799e
• Discovery of a warm, dusty giant planet around HIP65426
• Cloudless atmospheres for L/T dwarfs and extra-solar giant planets
• Simultaneous Detection of Water, Methane and Carbon Monoxide in the Atmosphere of Exoplanet HR8799b
• A self-consistent cloud model for brown dwarfs and young giant exoplanets: comparison with photometric and spectroscopic observations
• The JWST Early Release Science Program for Direct Observations of Exoplanetary Systems II: A 1 to 20 Micron Spectrum of the Planetary-Mass Companion VHS 1256-1257 b
• Detection and Characterization of Exoplanets using Projections on Karhunen-Loeve Eigenimages: Forward Modeling
• First direct detection of an exoplanet by optical interferometry; Astrometry and K-band spectroscopy of HR8799 e
• First light of the VLT planet finder SPHERE. IV. Physical and chemical properties of the planets around HR8799
• Directly Imaged L-T Transition Exoplanets in the Mid-Infrared
• M-band Imaging of the HR 8799 Planetary System Using an Innovative LOCI-based Background Subtraction Technique
• Interpreting the photometry and spectroscopy of directly imaged planets: a new atmospheric model applied to beta Pictoris b and SPHERE observations
• Gemini Planet Imager Spectroscopy of the HR 8799 planets c and d
• Resolved Submillimeter Observations of the HR 8799 and HD 107146 Debris Disks
• The Mid-Infrared Instrument for the James Webb Space Telescope, V: Predicted Performance of the MIRI Coronagraphs
• Resolving the Planetesimal Belt of HR 8799 with ALMA
• Deep exploration of the planets HR 8799 b, c, and d with moderate resolution spectroscopy
• Cloudless atmospheres for young low-gravity substellar objects
• Spatially resolved imaging of the inner Fomalhaut disk using JWST/MIRI
• Imaging low-mass planets within the habitable zone of α Centauri
• The JWST Early Release Science Program for the Direct Imaging & Spectroscopy of Exoplanetary Systems
• A detailed characterization of HR 8799's debris disk with ALMA in Band 7
• X-SHYNE: X-shooter spectra of young exoplanet analogs. I. A medium-resolution 0.65-2.5$\mu \mathrm{m}$ one-shot spectrum of VHS\,1256-1257 b
• Resolved Millimeter Observations of the HR 8799 Debris Disk
• Molecule mapping of HR8799b using OSIRIS on Keck: Strong detection of water and carbon monoxide, but no methane
• On the radial distribution of giant exoplanets at Solar System scales
• Atmospheric characterization of directly imaged exoplanets with JWST/MIRI
• Atmospheric Monitoring and Precise Spectroscopy of the HR 8799 Planets with SCExAO/CHARIS
• Deep orbital search for additional planets in the HR 8799 system
• Shaping HR8799's outer dust belt with an unseen planet
• The beta Pictoris system: Setting constraints on the planet and the disk structures at mid-IR wavelengths with NEAR
• New constraints on the HR 8799 planetary system from mid-infrared direct imaging

Cited by in corpus (15)

• Four-of-a-kind? Comprehensive atmospheric characterisation of the HR 8799 planets with VLTI/GRAVITY
• JWST MIRI Flight Performance: Imaging
• JWST-TST High Contrast: Living on the Wedge, or, NIRCam Bar Coronagraphy Reveals CO${}_2$ in the HR 8799 and 51 Eri Exoplanets' Atmospheres
• A PR drag origin for the Fomalhaut disk's pervasive inner dust: constraints on collisional strengths, icy composition, and embedded planets
• The compositions of the HR 8799 planets reflect accretion of both solids and metal-enriched gas
• The ALMA survey to Resolve exoKuiper belt Substructures (ARKS): VI. Asymmetries and offsets
• Characterization of debris disks observed with SPHERE
• JWST/MIRI observations of the young TWA 27 system: hydrocarbon disk chemistry, silicate clouds, evidence for a CPD
• Review and prospects of hot exozodiacal dust research for future exo-Earth direct imaging missions
• Combining high-contrast imaging with high-resolution spectroscopy: Actual on-sky MIRI/MRS results compared to expectations
• The MICADO first light imager for the ELT: Testing the Lyot coronograph prototypes
• Serendipitous observation of a white dwarf companion to a JWST/MIRI coronagraphic calibrator
• Observation of an Accreting Planetary-Mass Companion with Signs of Disk-Disk Interaction in Orion
• CoronaGraph Instrument Reference stars for Exoplanets (CorGI-REx) I. Preliminary Vetting and Implications for the Roman Coronagraph and Habitable Worlds Observatory
• The Nearest, Brightest Debris Disk Host Stars: Updated Photosphere Models and Dust Properties for Stars with Saturated 2MASS Photometry