Astrometric and photometric characterization of $\eta$ Tel B combining two decades of observations

Abstract

$\eta$ Tel is an 18 Myr system with a 2.09 M${}_{\odot }$ A-type star and an M7-M8 brown dwarf companion, $\eta$ Tel B, separated by 4.2'' (208 au). High-contrast imaging campaigns over 20 years have enabled orbital and photometric characterization. $\eta$ Tel B, bright and on a wide orbit, is ideal for detailed examination. We analyzed three new SPHERE/IRDIS coronagraphic observations to explore $\eta$ Tel B's orbital parameters, contrast, and surroundings, aiming to detect a circumplanetary disk or close companion. Reduced IRDIS data achieved a contrast of 1.0$\times 10^{-5}$, enabling astrometric measurements with uncertainties of 4 mas in separation and 0.2 degrees in position angle, the smallest so far. With a contrast of 6.8 magnitudes in the H band, $\eta$ Tel B's separation and position angle were measured as 4.218'' and 167.3 degrees, respectively. Orbital analysis using Orvara code, considering Gaia-Hipparcos acceleration, revealed a low eccentric orbit (e $\sim$ 0.34), inclination of 81.9 degrees, and semi-major axis of 218 au. $\eta$ Tel B's mass was determined to be 48 \MJup, consistent with previous calculations. No significant residual indicating a satellite or disk around $\eta$ Tel B was detected. Detection limits ruled out massive objects around $\eta$ Tel B with masses down to 1.6 \MJup at a separation of 33 au.

arXiv comment13 pages, 10 figures, accepted for publication in A&A (01/05/2024)

References in corpus (67)

• emcee: The MCMC Hammer
• Estimating distances from parallaxes. V: Geometric and photogeometric distances to 1.47 billion stars in Gaia Early Data Release 3
• New evolutionary models for pre-main sequence and main sequence low-mass stars down to the hydrogen-burning limit
• The effects of snowlines on C/O in planetary atmospheres
• Angular Differential Imaging: a Powerful High-Contrast Imaging Technique
• A giant planet imaged in the disk of the young star Beta Pictoris
• The NASA Exoplanet Archive: Data and Tools for Exoplanet Research
• Long-Term Stability of Planets in Binary Systems
• Detection and Characterization of Exoplanets and Disks using Projections on Karhunen-Loeve Eigenimages
• Discovery of a planetary-mass companion within the gap of the transition disk around PDS 70
• A Giant Planet Candidate near a Young Brown Dwarf
• SPHERE: the exoplanet imager for the Very Large Telescope
• The Geneva-Copenhagen Survey of the Solar neighbourhood III. Improved distances, ages, and kinematics
• Fundamental limitations of high contrast imaging set by small sample statistics
• PynPoint: An Image Processing Package for Finding Exoplanets
• On the diversity and statistical properties of protostellar discs
• Dynamic temperature selection for parallel-tempering in Markov chain Monte Carlo simulations
• A new set of atmosphere and evolution models for cool T-Y brown dwarfs and giant exoplanets
• Stellar and substellar companions from Gaia EDR3 -- Proper motion anomaly and resolved common proper motion pairs
• Predicting the Properties of Binary Stellar Systems: The Evolution of Accreting Protobinary Systems
• Discovery of a probable 4-5 Jupiter-mass exoplanet to HD 95086 by direct-imaging
• VIP: Vortex Image Processing package for high-contrast direct imaging
• The evolution of gravitationally unstable protoplanetary disks: fragmentation and possible giant planet formation
• Population-Level Eccentricity Distributions of Imaged Exoplanets and Brown Dwarf Companions: Dynamical Evidence for Distinct Formation Channels
• First light of the VLT planet finder SPHERE. III. New spectrophotometry and astrometry of the HR8799 exoplanetary system
• The formation of close binary systems
• A Candidate Substellar Companion to HR 7329
• SPHERE / ZIMPOL high resolution polarimetric imager. I. System overview, PSF parameters, coronagraphy, and polarimetry
• Extrasolar planets and brown dwarfs around A-F type stars VI. High precision RV survey of early type dwarfs with HARPS
• Astrometric and photometric accuracies in high contrast imaging: The SPHERE speckle calibration tool (SpeCal)
• A survey of young, nearby, and dusty stars to understand the formation of wide-orbit giant planets
• Protostellar fragmentation in a power-law density distribution
• orvara: An Efficient Code to Fit Orbits using Radial Velocity, Absolute, and/or Relative Astrometry
• Dynamical traceback age of the $\beta$ Pictoris moving group
• The Turbulent Origin of Outflow and Spin Misalignment in Multiple Star Systems
• Dynamical evolution of an eccentric planet and a less massive debris disc
• Performance of the VLT Planet Finder SPHERE I. Photometry and astrometry precision with IRDIS and IFS in laboratory
• VLT/SPHERE robust astrometry of the HR8799 planets at milliarcsecond-level accuracy Orbital architecture analysis with PyAstrOFit
• AF Lep b: the lowest mass planet detected coupling astrometric and direct imaging data
• Direct imaging discovery of a super-Jovian around the young Sun-like star AF Leporis
• Astrometric Accelerations as Dynamical Beacons: A Giant Planet Imaged Inside the Debris Disk of the Young Star AF Lep
• The Formation and Evolution of Wide-Orbit Stellar Multiples In Magnetized Clouds
• New Evidence for a Substellar Luminosity Problem: Dynamical Mass for the Brown Dwarf Binary Gl 417BC
• The Center of Light: Spectroastrometric Detection of Exomoons
• The LEECH Exoplanet Imaging Survey. Further constraints on the planet architecture of the HR 8799 system
• Resolved debris disk emission around eta Tel: a young Solar System or ongoing planet formation?
• The SPHERE infrared survey for exoplanets (SHINE)- I Sample definition and target characterization
• Alignment in star-debris disc systems seen by Herschel
• Circumplanetary disks around young giant planets: a comparison between core-accretion and disk instability
• Detecting exomoons from radial velocity measurements of self-luminous planets: application to observations of HR 7672 B and future prospects
• Extrasolar Binary Planets I: Formation by tidal capture during planet-planet scattering
• Search for associations containing young stars (SACY) VIII. An updated census of spectroscopic binary systems showing hints of non-universal multiplicity among these associations
• Discovery of a directly imaged planet to the young solar analog YSES 2
• High precision astrometry with a diffractive pupil telescope
• Star-disc (mis-)alignment in Rho Oph and Upper Sco: insights from spatially resolved disc systems with K2 rotation periods
• A HARPS RV search for planets around young nearby stars
• Further deep imaging of HR 7329 A (eta Tel A) and its brown dwarf companion B
• The Orbital Eccentricities of Directly Imaged Companions Using Observable-Based Priors: Implications for Population-level Distributions
• GPI Spectroscopy of the Mass, Age, and Metallicity Benchmark Brown Dwarf HD 4747 B
• The search for disks or planetary objects around directly imaged companions: A candidate around DH Tau B
• Upper limits on protolunar disc masses using ALMA observations of directly-imaged exoplanets
• Dynamical models to explain observations with SPHERE in planetary systems with double debris belts
• Detectability of satellites around directly imaged exoplanets and brown dwarfs
• Mid-infrared imaging of brown dwarfs in binary systems
• The SHARDDS survey: limits on planet occurrence rates based on point sources analysis via the Auto-RSM framework
• Ultracool dwarfs candidates based on six years of the Dark Energy Survey data
• A Radiatively Driven Wind from the eta Tel Debris Disk