Two new ultracool benchmark systems from WISE+2MASS

J. I. Gomes, D.J. Pinfield, F. Marocco, A. C. Day-Jones, B. Burningham, Z. H. Zhang, H.R.A. Jones, L. van Spaandonk, D. Weights

Research output: Contribution to journalArticlepeer-review

20 Citations (Scopus)
54 Downloads (Pure)

Abstract

We have used the Two-Micron All-Sky Survey and the Wide-field Infrared Survey Explorer to look for ultracool dwarfs that are part of multiple systems containing main-sequence stars. We cross-matched L dwarf candidates from the surveys with Hipparcos and Gliese stars, finding two new systems. The first system, G255-34AB, is an L2 dwarf companion to a K8 star, at a distance of 36 pc. We estimate its bolometric luminosity as log L/L-circle dot = -3.78 +/- 0.045 and T-eff = 2080 +/- 260 K. The second system, GJ499ABC, is a triple, with an L5 dwarf as a companion to a binary with an M4 and K5 star. These two new systems bring the number of L dwarf plus main-sequence star multiple systems to 24, which we discuss. We consider the binary fraction for L dwarfs and main-sequence stars, and further assess possible unresolved multiplicity within the full companion sample. This analysis shows that some of the L dwarfs in this sample might actually be unresolved binaries themselves, since their M-J appears to be brighter than the expected for their spectral types.

Original languageEnglish
Pages (from-to)2745-2755
Number of pages11
JournalMonthly Notices of the Royal Astronomical Society
Volume431
Issue number3
DOIs
Publication statusPublished - May 2013

Keywords

  • surveys
  • brown dwarfs
  • stars: low-mass
  • ALL-SKY SURVEY
  • COMMON PROPER MOTION
  • LOW-MASS STARS
  • BROWN DWARF COMPANIONS
  • SPECTRAL TYPE-L
  • FIELD L-DWARFS
  • COOL NEIGHBORS
  • T-DWARFS
  • SOLAR NEIGHBORHOOD
  • ADAPTIVE OPTICS

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