The Brown Dwarf Kinematics Project (BDKP. III. Parallaxes for 70 Ultracool Dwarfs

Abstract

We report parallax measurements for 70 ultracool dwarfs (UCDs) including 11 late-M, 32 L, and 27 T dwarfs. In this sample, 14 M and L dwarfs exhibit low surface gravity features, 6 are close binary systems, and 2 are metal-poor subdwarfs. We combined our new measurements with 114 previously published UCD parallaxes and optical mid- IR photometry to examine trends in spectral-type/absolute magnitude, and color color diagrams. We report new polynomial relations between spectral type and MJHK. Including resolved L/T transition binaries in the relations, we find no reason to differentiate between a bright (unresolved binary) and a faint (single source) sample across the L/T boundary. Isolating early T dwarfs, we find that the brightening of T0 T4 sources is prominent inMJ where there is a [1.2 1.4] mag difference.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Jun 10, 2012
Accession Number
ADA570900

Entities

People

  • Adam J. Burgasser
  • Andrew A. West
  • Frederick J. Vrba
  • Frederick M. Walter
  • Guillem Anglada-escude
  • Jacqueline K. Faherty
  • Kelle L. Cruz
  • Michael M. Shara
  • Nicole Van Der Bliek

Organizations

  • United States Naval Observatory Flagstaff Station

Tags

Communities of Interest

  • C4I
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Accuracy
  • Catalogs
  • Celestial Brightness
  • Data Analysis
  • Data Sets
  • Detectors
  • Jet Propulsion
  • Measurement
  • Observation
  • Observatories
  • Optical Detectors
  • Photometry
  • Physical Properties
  • Polynomials
  • Standards
  • Thickness
  • Transitions

Fields of Study

  • Physics

Readers

  • Astronomy and Astrophysics.
  • Calculus or Mathematical Analysis
  • Space/Atmospheric Physics.