YSES 2b is a background star: Differential astrometric M-dwarf measurements in time

Abstract

We wish to confirm the nature of YSES 2b, a purportedly faint companion of the young star YSES 2. We used on-sky observations from SPHERE and GRAVITY to measure the astrometric position of 2b with respect to the star YSES 2, and examined the competing hypotheses of (i) a bound substellar companion versus (ii) a distant unrelated background source with a non-zero proper motion. YSES 2b appears to be a late-type M-dwarf star over 2 kiloparsecs behind the star YSES 2. It has a transverse velocity of about 300 km/s and is located within one of the spiral arms of the Galaxy. The main discriminant was multiple epochs of GRAVITY astrometry that identified the sub-milliarcsecond parallactic motion of the star.

arXiv comment8 pages, 6 figures, 2 tables

References in corpus (37)

• Astropy: A Community Python Package for Astronomy
• emcee: The MCMC Hammer
• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• Gaia Data Release 3: Summary of the content and survey properties
• Binary companions of evolved stars in APOGEE DR14: Search method and catalog of ~5,000 companions
• The SIMBAD astronomical database
• dynesty: A Dynamic Nested Sampling Package for Estimating Bayesian Posteriors and Evidences
• Estimating distances from parallaxes. V: Geometric and photogeometric distances to 1.47 billion stars in Gaia Early Data Release 3
• Multimodal nested sampling: an efficient and robust alternative to MCMC methods for astronomical data analysis
• X-ray spectral modelling of the AGN obscuring region in the CDFS: Bayesian model selection and catalogue
• Evolutionary models for very-low-mass stars and brown dwarfs with dusty atmospheres
• The Limiting Effects of Dust in Brown Dwarf Model Atmospheres
• Detection and Characterization of Exoplanets and Disks using Projections on Karhunen-Loeve Eigenimages
• First Light for GRAVITY: Phase Referencing Optical Interferometry for the Very Large Telescope Interferometer
• SPHERE: the exoplanet imager for the Very Large Telescope
• PynPoint: An Image Processing Package for Finding Exoplanets
• Photometric characterization of exoplanets using angular and spectral differential imaging
• From binaries to multiples I: Data on F and G dwarfs within 67 pc of the Sun
• PARSEC V2.0: Stellar tracks and isochrones of low and intermediate mass stars with rotation
• First light of the VLT planet finder SPHERE. III. New spectrophotometry and astrometry of the HR8799 exoplanetary system
• Peering into the formation history of beta Pictoris b with VLTI/GRAVITY long baseline interferometry
• MIRACLES: atmospheric characterization of directly imaged planets and substellar companions at 4-5 $\mu$m. I. Photometric analysis of $\beta$ Pic b, HIP 65426 b, PZ Tel B and HD 206893 B
• Direct confirmation of the radial-velocity planet $\beta$ Pic c
• High-contrast imaging of Sirius~A with VLT/SPHERE: Looking for giant planets down to one astronomical unit
• Performance of the VLT Planet Finder SPHERE I. Photometry and astrometry precision with IRDIS and IFS in laboratory
• Direct Imaging Discovery of a Jovian Exoplanet Within a Triple Star System
• Two Directly Imaged, Wide-orbit Giant Planets around the Young, Solar Analog TYC 8998-760-1
• The GRAVITY fringe tracker
• PynPoint: a modular pipeline architecture for processing and analysis of high-contrast imaging data
• The Young Suns Exoplanet Survey: Detection of a wide orbit planetary mass companion to a solar-type Sco-Cen member
• Discovery of a directly imaged planet to the young solar analog YSES 2
• Evidence that the Directly-Imaged Planet HD 131399 Ab is a Background Star
• First direct detection of a polarized companion outside of a resolved circumbinary disk around CS Cha
• Silicate clouds and a circumplanetary disk in the YSES-1 exoplanet system
• Apodization in high-contrast long-slit spectroscopy. II. Concept validation and first on-sky results with VLT/SPHERE
• CS Cha B: A disc-obscured M-type star mimicking a polarised planetary companion
• A catalogue of dual-field interferometric binary calibrators

Cited by in corpus (2)

• WIde Separation Planets In Time (WISPIT): Two directly imaged exoplanets around the Sun-like stellar binary WISPIT 1
• Direct Imaging Discovery of Giant Exoplanet $\beta$ Pictoris d: A Decade-Long Game of Hide-and-Seek