VLT/SPHERE astrometric confirmation and orbital analysis of the brown dwarf companion HR 2562 B

Abstract

Context. A low-mass brown dwarf has been recently imaged around HR 2562 (HD 50571), a star hosting a debris disk resolved in the far infrared. Interestingly, the companion location is compatible with an orbit coplanar with the disk and interior to the debris belt. This feature makes the system a valuable laboratory to analyze the formation of substellar companions in a circumstellar disk and potential disk-companion dynamical interactions. Aims. We aim to further characterize the orbital motion of HR 2562 B and its interactions with the host star debris disk. Methods. We performed a monitoring of the system over ~10 months in 2016 and 2017 with the VLT/SPHERE exoplanet imager. Results. We confirm that the companion is comoving with the star and detect for the first time an orbital motion at high significance, with a current orbital motion projected in the plane of the sky of 25 mas (~0.85 au) per year. No orbital curvature is seen in the measurements. An orbital fit of the SPHERE and literature astrometry of the companion without priors on the orbital plane clearly indicates that its orbit is (quasi-)coplanar with the disk. To further constrain the other orbital parameters, we used empirical laws for a companion chaotic zone validated by N-body simulations to test the orbital solutions that are compatible with the estimated disk cavity size. Non-zero eccentricities (>0.15) are allowed for orbital periods shorter than 100 yr, while only moderate eccentricities up to ~0.3 for orbital periods longer than 200 yr are compatible with the disk observations. A comparison of synthetic Herschel images to the real data does not allow us to constrain the upper eccentricity of the companion.

arXiv commentAccepted for publication in A&A. 14 pages, 14 figures, 3 tables. Updated to match published paper. Bug in the computation of the distributions of times at periastron passages corrected, minor effects on other orbital parameters

References in corpus (56)

• PARSEC: stellar tracks and isochrones with the PAdova and TRieste Stellar Evolution Code
• Gaia Data Release 1. Summary of the astrometric, photometric, and survey properties
• Direct Imaging of Multiple Planets Orbiting the Star HR 8799
• Evolutionary models for cool brown dwarfs and extrasolar giant planets. The case of HD 20945
• New evolutionary models for pre-main sequence and main sequence low-mass stars down to the hydrogen-burning limit
• Images of a fourth planet orbiting HR 8799
• A giant planet imaged in the disk of the young star Beta Pictoris
• Long-Term Stability of Planets in Binary Systems
• New constraints on the chemical evolution of the solar neighbourhood and Galactic disc(s). Improved astrophysical parameters for the Geneva-Copenhagen Survey
• EXOFAST: A fast exoplanetary fitting suite in IDL
• Discovery and spectroscopy of the young Jovian planet 51 Eri b with the Gemini Planet Imager
• Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 parsecs: The Southern Sample
• Stellar, Brown Dwarf, and Multiple Star Properties from Hydrodynamical Simulations of Star Cluster Formation
• Fundamental limitations of high contrast imaging set by small sample statistics
• Extrasolar planet population synthesis IV. Correlations with disk metallicity, mass and lifetime
• Photometric characterization of exoplanets using angular and spectral differential imaging
• Characterization of Dusty Debris Disks: the IRAS and Hipparcos Catalogs
• Disk eccentricity and embedded planets
• Variations on Debris Disks: Icy Planet Formation at 30-150 AU for 1-3 Solar Mass Main Sequence Stars
• Nearby debris disk systems with high fractional luminosity reconsidered
• Orbital characterization of the βPictoris b giant planet
• Chromospheric activity as age indicator
• Performance of the VLT Planet Finder SPHERE II. Data analysis and Results for IFS in laboratory
• Predictions for the secondary CO, C and O gas content of debris discs from the destruction of volatile-rich planetesimals
• Towards a Population Synthesis Model of Objects formed by Self-Gravitating Disc Fragmentation and Tidal Downsizing
• Direct exoplanet detection and characterization using the ANDROMEDA method: Performance on VLT/NaCo data
• Confirmation of the planet around HD 95086 by direct imaging
• Astrometric and photometric accuracies in high contrast imaging: The SPHERE speckle calibration tool (SpeCal)
• High-contrast Imaging Search for Planets and Brown Dwarfs around the Most Massive Stars in the Solar Neighborhood
• Disk Radii and Grain Sizes in Herschel-Resolved Debris Disks
• Highly inclined and eccentric massive planets I: Planet-disc interactions
• Outer edges of debris discs: how sharp is sharp?
• The stability and fates of hierarchical two-planet systems
• Structure and evolution of debris disks around F-type stars: I. Observations, database and basic evolutionary aspects
• Spiral Structure when Setting up Pericentre Glow: Possible Giant Planets at Hundreds of AU in the HD141569 Disk
• The dust grain size - stellar luminosity trend in debris discs
• The VLT/NaCo Large program to probe the occurrence of exoplanets and brown dwarfs in wide orbits: I- Sample definition and characterization
• Discovery of a low-mass companion inside the debris ring surrounding the F5V star HD206893
• Dependence of a planet's chaotic zone on particle eccentricity: the shape of debris disc inner edges
• Design, analysis and test of a microdots apodizer for the Apodized Pupil Lyot Coronagraph
• Astrometric Monitoring of the HR 8799 Planets: Orbit Constraints from Self-Consistent Measurements
• SPHERE IRDIS and IFS astrometric strategy and calibration
• Herschel's "Cold Debris Disks": Background Galaxies or Quiescent Rims of Planetary Systems?
• Discovery of a Substellar Companion to the Nearby Debris Disk Host HR 2562
• Stirring in massive, young debris discs from spatially resolved Herschel images
• LBT observations of the HR 8799 planetary system: First detection of HR8799e in H band
• The LEECH Exoplanet Imaging Survey. Further constraints on the planet architecture of the HR 8799 system
• GPI PSF subtraction with TLOCI: the next evolution in exoplanet/disk high-contrast imaging
• The fragmentation criteria in local vertically stratified self-gravitating disk simulations
• Constraining the orbits of sub-stellar companions imaged over short orbital arcs
• Dynamical models to explain observations with SPHERE in planetary systems with double debris belts
• On the cavity of a debris disc carved by a giant planet
• New spectro-photometric characterization of the substellar object HR 2562 B using SPHERE
• Imaged sub-stellar companions: not as eccentric as they appear? The effect of an unseen inner mass on derived orbits
• Theory of planet formation
• VLT/SPHERE deep insight of NGC 3603's core: Segregation or confusion?

Cited by in corpus (14)

• Population-Level Eccentricity Distributions of Imaged Exoplanets and Brown Dwarf Companions: Dynamical Evidence for Distinct Formation Channels
• The polarimetric imaging mode of VLT/SPHERE/IRDIS I: Description, data reduction and observing strategy
• Rotation Periods, Inclinations, and Obliquities of Cool Stars Hosting Directly Imaged Substellar Companions: Spin-Orbit Misalignments are Common
• The SPHERE infrared survey for exoplanets (SHINE)- I Sample definition and target characterization
• Hint of curvature in the orbital motion of the exoplanet 51 Eridani b using 3 years of VLT/SPHERE monitoring
• The Orbital Eccentricities of Directly Imaged Companions Using Observable-Based Priors: Implications for Population-level Distributions
• The search for disks or planetary objects around directly imaged companions: A candidate around DH Tau B
• High-contrast observations of brown dwarf companion HR 2562 B with the vector Apodizing Phase Plate coronagraph
• Applying a temporal systematics model to vector Apodizing Phase Plate coronagraphic data: TRAP4vAPP
• Distinct Rotational Evolution of Giant Planets and Brown Dwarf Companions
• Polarimetric differential imaging with VLT/NACO. A comprehensive PDI pipeline for NACO data (PIPPIN)
• A High-Resolution Spectroscopic Survey of Directly Imaged Companion Hosts: II. Diversity in C/O Ratios among Host Stars
• New constraints on the presence of debris disks around G 196-3 B and VHS J125601.92-125723.9 b
• Lessons learned from SPHERE for the astrometric strategy of the next generation of exoplanet imaging instruments