Dynamical masses for the nearest brown dwarf binary: Epsilon Indi Ba, Bb

C. V. Cardoso; M. J. McCaughrean; R. R. King; L. M. Close; R. -D. Scholz; R. Lenzen; W. Brandner; N. Lodieu; H. Zinnecker

doi:10.1063/1.3099160

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arXiv · 0811.0588

Dynamical masses for the nearest brown dwarf binary: Epsilon Indi Ba, Bb

C. V. Cardoso·M. J. McCaughrean·R. R. King·L. M. Close·R. -D. Scholz·R. Lenzen·W. Brandner·N. Lodieu·H. Zinnecker

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Abstract

We present preliminary astrometric results for the closest known brown dwarf binary to the Sun: Epsilon Indi Ba, Bb at a distance of 3.626 pc. Via ongoing monitoring of the relative separation of the two brown dwarfs (spectral types T1 and T6) with the VLT NACO near-IR adaptive optics system since June 2004, we obtain a model-independent dynamical total mass for the system of 121 MJup, some 60% larger than the one obtained by McCaughrean et al. (2004), implying that the system may be as old as 5 Gyr. We have also been monitoring the absolute astrometric motions of the system using the VLT FORS2 optical imager since August 2005 to determine the individual masses. We predict a periastron passage in early 2010, by which time the system mass will be constrained to < 1 MJup and we will be able to determine the individual masses accurately in a dynamical, model-independent manner.

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C. V. Cardoso, M. J. McCaughrean, R. R. King, L. M. Close, R. -D. Scholz, R. Lenzen, W. Brandner, N. Lodieu, H. Zinnecker. 2008-11-04. Dynamical masses for the nearest brown dwarf binary: Epsilon Indi Ba, Bb. https://doi.org/10.1063/1.3099160

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