Volume 561, January 2014
|Number of page(s)||5|
|Section||Stellar structure and evolution|
|Published online||17 January 2014|
Neighbours hiding in the Galactic plane, a new M/L dwarf candidate for the 8 pc sample
Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, 14482 Potsdam, Germany
Received: 8 November 2013
Accepted: 12 December 2013
Aims. Using Wide-field Infrared Survey Explorer (WISE) data and previous optical and near-infrared sky surveys, we try to identify still missing stellar and substellar neighbours of the Sun.
Methods. When checking the brightest red WISE sources for proper motions and colours expected for nearby M and L dwarfs, we also approached the thin Galactic plane. Astrometry (proper motion and parallax measurements) and the available photometry were used to obtain first estimates of the distance and type of nearby candidates.
Results. We have discovered WISE J072003.20−084651.2, an object with moderately high proper motion (μ ≈ 120 mas/yr) that lies at low Galactic latitude (b = +2.3°), with similar brightness (J ≈ 10.6, w2 ≈ 8.9) and colours (I − J ≈ 3.2, J − Ks ≈ 1.2, w1 − w2 ≈ 0.3) as the nearest known M-type brown dwarf LP 944-20. With a photometric classification as an M9 ± 1 dwarf, its photometric distance lies in the range between about 5 and 7 pc, based on comparison with absolute magnitudes of LP 944-20 alone or of a sample of M8-L0 dwarfs. The slightly larger distance derived from our preliminary trigonometric parallax (7.0 ± 1.9 pc) may indicate a close binary nature. The new neighbour is an excellent target for planet search and low-mass star/brown dwarf studies.
Key words: astrometry / proper motions / stars: distances / stars: kinematics and dynamics / brown dwarfs / solar neighborhood
© ESO, 2014
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.