2015A&A...581A..73L


Query : 2015A&A...581A..73L

2015A&A...581A..73L - Astronomy and Astrophysics, volume 581A, 73-73 (2015/9-1)

VLT X-Shooter spectroscopy of the nearest brown dwarf binary.

LODIEU N., ZAPATERO OSORIO M.R., REBOLO R., BEJAR V.J.S., PAVLENKO Y. and PEREZ-GARRIDO A.

Abstract (from CDS):

The aim of the project is to characterise the two components of the brown dwarf system nearest to the Sun, WISE J104915.57-531906.1 (also called Luhman 16AB) at optical and near-infrared wavelengths. We obtained high signal-to-noise intermediate-resolution (R∼6000-11000) optical (600-1000nm) and near-infrared (1000-2480nm) spectra of each component of Luhman 16AB with the X-Shooter instrument on the Very Large Telescope. We classify the primary and secondary of the Luhman16 system as L6-L7.5 and T0±1, respectively, in agreement with previous measurements published in the literature. We present measurements of the lithium pseudo-equivalent widths, which appear of similar strength in both components (8.2±1.0Å for the L and 8.4±1.5Å for the T component). The presence of lithium (7Li) in both components implies masses lower than 0.06M, while the comparison with models suggests lower limits of 0.04M. The detection of lithium in the T component is the first of its kind. Similarly, we assess the strength of other alkali lines (e.g. pseudo-equivalent widths of 6-7Å for RbI and 4-7Å for CsI) present in the optical and near-infrared regions and compare with estimates for L and T dwarfs. We also derive effective temperatures and luminosities of each component of the binary: -4.66±0.08dex and 1305+180–135K for the L dwarf and -4.68±0.13dex and 1320+185–135K for the T dwarf. According to our radial velocity determinations, the binary does not appear to belong to any of the well-known moving group. Our preliminary theoretical analysis of the optical and J-band spectra indicates that the L- and T-type spectra can be reproduced with a single temperature and gravity but different relative chemical abundances, which strongly affects the spectral energy distribution of L/T transition objects.

Abstract Copyright:

Journal keyword(s): techniques: spectroscopic - brown dwarfs - binaries: general - stars: fundamental parameters

VizieR on-line data: <Available at CDS (J/A+A/581/A73): spluh16a.dat spluh16b.dat>

Simbad objects: 15

goto Full paper

goto View the references in ADS

Number of rows : 15
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2024
#notes
1 2MASSI J0103320+193536 BD* 01 03 32.03712 +19 35 36.1824           L6V 77 0
2 2MASSW J0310599+164816 BD* 03 10 59.86560 +16 48 15.5988           L8V 49 0
3 2MASSI J0423485-041403 BD* 04 23 48.5763811987 -04 14 03.246502948           L6.5+T2 125 0
4 SDSS J083717.21-000018.0 BD* 08 37 17.20032 -00 00 19.3608           T1 51 0
5 2MASS J08503593+1057156 BD* 08 50 35.93400 +10 57 15.6168       22.466 20.349 L6.5+L8.5 78 0
6 NAME Luhman 16A BD* 10 49 14.0238534572 -53 19 05.005159625           L7.5 48 0
7 NAME Luhman 16B BD* 10 49 14.0744805001 -53 19 05.800116097           T0.5 59 0
8 NAME Luhman 16 ** 10 49 18.91536 -53 19 10.0776   16.86 16.20   14.95 L7.5+T0.5 94 0
9 HD 100663 * 11 34 39.7642146240 -53 01 43.435127928   8.93 8.92     B9V 13 0
10 2MASS J12545393-0122474 BD* 12 54 53.9040607346 -01 22 47.399401142           T2e: 150 0
11 2MASSW J1507476-162738 BD* 15 07 47.6758255542 -16 27 40.113982846     22.136 18.928 16.579 L5V 199 0
12 2MASS J16322911+1904407 BD* 16 32 29.11416 +19 04 40.7136       22.42 19.98 L8V 131 0
13 NAME Barnard's star BY* 17 57 48.4984700685 +04 41 36.113879676 12.497 11.24 9.511 8.298 6.741 M4V 810 2
14 * eps Ind PM* 22 03 21.6536261624 -56 47 09.522795714   5.75 4.69     K5V 548 0
15 * eps Ind B BD* 22 04 10.5951812451 -56 46 58.239102418     24.12 20.8 15.60 T1V+T6V 161 1

To bookmark this query, right click on this link: simbad:objects in 2015A&A...581A..73L and select 'bookmark this link' or equivalent in the popup menu