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arXiv · 1312.1303

Possible astrometric discovery of a substellar companion to the closest binary brown dwarf system WISE J104915.57-531906.1

H. M. J. Boffin·D. Pourbaix·K. Muzic·V. D. Ivanov·R. Kurtev·Y. Beletsky·A. Mehner·J. P. Berger·J. H. Girard·D. Mawet
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Abstract

Using FORS2 on the Very Large Telescope, we have astrometrically monitored over a period of two months the two components of the brown dwarf system WISE J104915.57-531906.1, the closest one to the Sun. Our astrometric measurements - with a relative precision at the milli-arcsecond scale - allow us to detect the orbital motion and derive more precisely the parallax of the system, leading to a distance of 2.020+/-0.019 pc. The relative orbital motion of the two objects is found to be perturbed, which leads us to suspect the presence of a substellar companion around one of the two components. We also perform VRIz photometry of both components and compare with models. We confirm the flux reversal of the T dwarf.

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H. M. J. Boffin, D. Pourbaix, K. Muzic, V. D. Ivanov, R. Kurtev, Y. Beletsky, A. Mehner, J. P. Berger, J. H. Girard, D. Mawet. 2013-12-04. Possible astrometric discovery of a substellar companion to the closest binary brown dwarf system WISE J104915.57-531906.1. https://doi.org/10.1051/0004-6361/201322975

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