High-contrast, high-angular resolution view of the GJ 367 exoplanet system

Abstract

We search for additional companions in the GJ 367 exoplanet system, and aim at better constraining its age and evolutionary status. We analyse high contrast direct imaging observations obtained with HST/NICMOS, VLT/NACO, and VLT/SPHERE. We investigate and critically discuss conflicting age indicators based on theoretical isochrones and models for Galactic dynamics. A comparison of GAIA EDR3 parallax and photometric measurements with theoretical isochrones suggest a young age $\le$60 Myr for GJ 367. The star's Galactic kinematics exclude membership to any nearby young moving group or stellar stream. Its highly eccentric Galactic orbit, however, is atypical for a young star. Age estimates considering Galactic dynamical evolution are most consistent with an age of 1 to 8 Gyr. We find no evidence for a significant mid-infrared excess in the WISE bands, suggesting the absence of warm dust in the GJ 367 system. The direct imaging data provide significantly improved detection limits compared to previous studies. At 530 mas (5 au) separation, the SPHERE data achieve a 5 sigma contrast of $2.6\times 10^{-6}$. The data exclude the presence of a stellar companion at projected separations $\ge$0.4 au. At projected separations $\ge$5 au we can exclude substellar companions with a mass $\ge$ 1.5 M${}_{\mathrm{Jup}}$ for an age of 50 Myr, and $\ge$ 20 M${}_{\mathrm{Jup}}$ for an age of 5 Gyr. By applying the stellar parameters corresponding to the 50 Myr isochrone, we derive a bulk density of ${\rho }_{\mathrm{planet}}=6.2$ g/cm${}^3$ for GJ 367b, which is 25% smaller than a previous estimate.

arXiv comment9 pages, 8 figures, accepted by MNRAS

References in corpus (41)

• The Gaia mission
• Gaia Data Release 2: The astrometric solution
• MESA Isochrones and Stellar Tracks (MIST) 0: Methods for the construction of stellar isochrones
• Evolutionary models for cool brown dwarfs and extrasolar giant planets. The case of HD 20945
• galpy: A Python Library for Galactic Dynamics
• New evolutionary models for pre-main sequence and main sequence low-mass stars down to the hydrogen-burning limit
• Local stellar kinematics from Hipparcos data
• Angular Differential Imaging: a Powerful High-Contrast Imaging Technique
• Detection of the gravitational redshift in the orbit of the star S2 near the Galactic centre massive black hole
• SPHERE: the exoplanet imager for the Very Large Telescope
• The Ages of Stars
• BANYAN. XI. The BANYAN $\Sigma$ multivariate Bayesian algorithm to identify members of young associations within 150 pc
• Model Atmospheres for M (Sub)Dwarfs: I. The base model grid
• Bayesian analysis to identify new star candidates in nearby young stellar kinematic groups
• The Hipparcos-Gaia Catalog of Accelerations: Gaia EDR3 Edition
• Stellar and substellar companions from Gaia EDR3 -- Proper motion anomaly and resolved common proper motion pairs
• Rotation periods of late-type dwarf stars from time-series high-resolution spectroscopy of chromospheric indicators
• The UV and X-ray activity of the M dwarfs within 10pc of the Sun
• Radius Dependent Angular Momentum Evolution in Low-Mass Stars. I
• Magnetic activity in the HARPS M-dwarf sample. The rotation-activity relationship for very low-mass stars through R'HK
• A public HARPS radial velocity database corrected for systematic errors
• On the Age and Binarity of Fomalhaut
• Measuring Radial Orbit Migration in the Milky Way Disk
• 3D mapping of young stars in the solar neighbourhood with Gaia DR2
• Local Stellar Kinematics from RAVE Data: I. Local Standard of Rest
• Direct exoplanet detection and characterization using the ANDROMEDA method: Performance on VLT/NaCo data
• Keeping it Cool: Much Orbit Migration, yet Little Heating, in the Galactic Disk
• K2 Rotation Periods for low-mass Hyads and the Implications for Gyrochronology
• The Solar Neighborhood XXVIII: The Multiplicity Fraction of Nearby Stars from 5 to 70 AU and the Brown Dwarf Desert Around M Dwarfs
• LACEwING: A New Moving Group Analysis Code
• Design, analysis and test of a microdots apodizer for the Apodized Pupil Lyot Coronagraph
• Stellar clustering shapes the architectures of planetary systems
• GJ 367b: A dense ultra-short period sub-Earth planet transiting a nearby red dwarf star
• New stellar encounters discovered in the second Gaia data release
• The Nancy Grace Roman Space Telescope Coronagraph Instrument (CGI) Technology Demonstration
• Connecting substellar and stellar formation. The role of the host star's metallicity
• Planets Across Space and Time (PAST). I. Characterizing the Memberships of Galactic Components and Stellar Ages: Revisiting the Kinematic Methods and Applying to Planet Host Stars
• Direct imaging of molten protoplanets in nearby young stellar associations
• Single stars in the Hyades open cluster. Fiducial sequence for testing stellar and atmospheric models
• Orbital and spectral characterization of the benchmark T-type brown dwarf HD 19467B
• Catalogue of exoplanets accessible in reflected starlight to the Nancy Grace Roman Space Telescope. A population study and prospects for phase-curve measurements

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