Substellar Hyades Candidates from the UKIRT Hemisphere Survey

Abstract

We have used data from the UKIRT Hemisphere Survey (UHS) to search for substellar members of the Hyades cluster. Our search recovered several known substellar Hyades members, and two known brown dwarfs that we suggest may be members based on a new kinematic analysis. We uncovered thirteen new substellar Hyades candidates, and obtained near-infrared follow-up spectroscopy of each with IRTF/SpeX. Six candidates with spectral types between M7 and L0 are ruled out as potential members based on their photometric distances ($\gtrsim$100 pc). The remaining seven candidates, with spectral types between L5 and T4, are all potential Hyades members, with five showing strong membership probabilities based on BANYAN $\Sigma$ and a convergent point analysis. Distances and radial velocities are still needed to confirm Hyades membership. If confirmed, these would be some of the lowest mass free-floating members of the Hyades yet known, with masses as low as $\sim$30 $M_{\mathrm{Jup}}$. An analysis of all known substellar Hyades candidates shows evidence that the full extent of the Hyades has yet to be probed for low-mass members, and more would likely be recovered with deeper photometric and astrometric investigations.

Accepted to AJ

References in corpus (20)

• The UKIRT Infrared Deep Sky Survey (UKIDSS)
• The Evolution of L and T Dwarfs in Color-Magnitude Diagrams
• The UKIRT Wide Field Camera ZYJHK Photometric System: Calibration from 2MASS
• Gaia Early Data Release 3: The Gaia Catalogue of Nearby Stars
• The CatWISE2020 Catalog
• The Hawaii Infrared Parallax Program. II. Young Ultracool Field Dwarfs
• Subtle Signatures of Multiplicity in Late-type Dwarf Spectra: The Unresolved M8.5 + T5 Binary 2MASS J03202839-0446358
• The Field Substellar Mass Function Based on the Full-sky 20-pc Census of 525 L, T, and Y Dwarfs
• The UKIRT Hemisphere Survey: Definition and J-band Data Release
• WIYN Open Cluster Study. LXXV. Testing the Metallicity Dependence of Stellar Lithium Depletion Using Hyades-Aged Clusters. 1. Hyades & Praesepe
• Extended stellar systems in the solar neighborhood - I. The tidal tails of the Hyades
• Brown dwarfs and very low mass stars in the Hyades cluster : a dynamically evolved mass function
• A Search for L/T Transition Dwarfs With Pan-STARRS1 and WISE. II. L/T Transition Atmospheres and Young Discoveries
• The Hawaii Infrared Parallax Program. IV. A Comprehensive Parallax Survey of L0-T8 dwarfs with UKIRT
• A 3D view of the Hyades stellar and sub-stellar population
• The Hawaii Infrared Parallax Program. V. New T-Dwarf Members and Candidate Members of Nearby Young Moving Groups
• Spectroscopy of Hyades L dwarf candidates
• L dwarfs in the Hyades
• A Statistical Survey of Peculiar L and T Dwarfs in SDSS, 2MASS, and WISE
• A new L5 brown dwarf member of the Hyades cluster with chromospheric activity

Cited by in corpus (1)

• Redder than Red: Discovery of an Exceptionally Red L/T Transition Dwarf