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A young binary Brown Dwarf in the R-CrA star formation region

H. Bouy·W. Brandner·E. L. Martin·X. Delfosse·F. Allard·I. Baraffe·T. Forveille·R. Demarco
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Abstract

We present imaging and spectroscopic observations with HST (WFPC2, ACS/HRC and STIS), VLT (FORS2) and Keck (HIRES) of the dM8 ultra-cool dwarf DENIS-P J185950.9-370632, located in the R-CrA region. The presence of lithium absorption at 670.8 nm and the strong Halpha emission indicate a young age and a sub-stellar mass. Our diffraction-limited images resolve a companion at the separation limit of HST/ACS (~0.06"). The 2.1 mJy flux in the LW2 filter (5.0-8.5 microns) of the Infrared Space Observatory (see 1999A&A...350..883) likely corresponds to an infrared excess, suggesting the presence of circumstellar material. Proper motion and photometric measurements, as well as the Halpha activity, confirm membership in the R-CrA star forming region. If confirmed by further observations, DENIS-P J185950.9-370632 would be the first accreting sub-stellar multiple system observed to date.

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H. Bouy, W. Brandner, E. L. Martin, X. Delfosse, F. Allard, I. Baraffe, T. Forveille, R. Demarco. 2004-04-29. A young binary Brown Dwarf in the R-CrA star formation region. https://doi.org/10.1051/0004-6361%3A20035954

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