2013A&A...557A..43B


Query : 2013A&A...557A..43B

2013A&A...557A..43B - Astronomy and Astrophysics, volume 557A, 43-43 (2013/9-1)

An overlooked brown dwarf neighbour (T7.5 at d ∼ 5 pc) of the Sun and two additional T dwarfs at about 10 pc.

BIHAIN G., SCHOLZ R.-D., STORM J. and SCHNURR O.

Abstract (from CDS):

Although many new brown dwarf (BD) neighbours have recently been discovered thanks to new sky surveys in the mid- and near-infrared (MIR, NIR), their numbers are still more than five times lower than those of stars in the same volume. Our aim is to detect and classify new BDs to eventually complete their census in the immediate solar neighbourhood. We combined multi-epoch data from sky surveys at different wavelengths to detect BD neighbours of the Sun by their high proper motion (HPM). We concentrated on relatively bright MIR (w2<13.5) BD candidates from the Wide-field Infrared Survey Explorer (WISE) expected to be so close to the Sun that they may also be seen in older NIR (Two Micron All Sky Survey - 2MASS -; DEep Near-Infrared Survey - DENIS) or even red optical (Sloan Digital Sky Survey (SDSS) i- and z-band, SuperCOSMOS Sky Surveys (SSS) I-band) surveys. With low-resolution NIR spectroscopy we classified the new BDs and estimated their distances and velocities. We have discovered the HPM (µ∼470 mas/yr) T7.5 dwarf, WISE J0521+1025, which is at d=5.0±1.3pc from the Sun the nearest known T dwarf in the northern sky, and two early T dwarfs, WISE J0457-0207 (T2) and WISE J2030+0749 (T1.5), with proper motions of ∼120 and ∼670mas/yr and distances of 12.5±3.1pc and 10.5±2.6pc, respectively. The last one was independently discovered and also classified as a T1.5 dwarf by Mace and coworkers. All three show thin disc kinematics. They may have been overlooked in the past owing to overlapping images and because of problems with matching objects between different surveys and measuring their proper motions.

Abstract Copyright:

Journal keyword(s): astrometry - proper motions - stars: distances - brown dwarfs - stars: kinematics and dynamics - solar neighborhood

Simbad objects: 12

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Number of rows : 12
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2021
#notes
1 2MASSI J0415195-093506 BD* 04 15 19.54368 -09 35 06.6732           T8.0 151 0
2 WISE J045746.08-020719.2 BD* 04 57 46.088 -02 07 19.24           T2 2 0
3 2MASS J05212615+1025328 BD* 05 21 26.157 +10 25 32.88           T7.5 4 0
4 2MASSI J0727182+171001 BD* 07 27 18.24600 +17 10 01.2072           T7.0 77 0
5 SDSS J083717.21-000018.0 BD* 08 37 17.20032 -00 00 19.3608           T1 42 0
6 NAME Luhman 16 ** 10 49 18.91536 -53 19 10.0776   16.86 16.20   14.95 L7.5+T0.5 79 0
7 2MASS J12095613-1004008 BD* 12 09 56.13096 -10 04 00.8076           T2+T7.5 51 0
8 2MASS J12171110-0311131 BD* 12 17 11.10288 -03 11 13.1748           T7.5 76 0
9 2MASS J12545393-0122474 BD* 12 54 53.9040607346 -01 22 47.399401142           T2e: 136 0
10 ULAS J130041.74+122114.7 BD* 13 00 42.08415 +12 21 15.0536         23.28 T8.5p 105 0
11 2MASS J14162408+1348263 BD* 14 16 24.0749913652 +13 48 26.176168678           L5 61 0
12 2MASS J20304235+0749358 BD* 20 30 42.3329934879 +07 49 35.784998811           T1.5 13 0

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2021.08.04-14:15:35

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