A non-uniform distribution of the nearest brown dwarfs
  The census of solar neighbours is still complemented by new discoveries,
mainly of very low-mass, faint dwarfs, close to or within the substellar
domain. These discoveries contribute to a better understanding of the field
population; its origin in terms of Galactic dynamics and (sub)stellar formation
and evolution. Also, the nearest stars and brown dwarfs at any given age allow
the most precise direct characterization, including the search for planetary
companions. We aim to further assess the substellar census on the Galactic
plane. We projected the 136 stars and 26 brown dwarfs known at <6.5 pc on the
Galactic plane and evaluated their distributions. Stars present a uniform- and
brown dwarfs a non-uniform distribution, with 21 objects behind the Sun and
only five ahead relative to the direction of rotation of the Galaxy. This
substellar configuration has a probability of 0.098$^{+10.878}_{-0.098}$%
relative to uniformity. The helio- and geocentric nature of the distribution
suggests it might result in part from an observational bias, which if
compensated for by future discoveries, might increase the brown-dwarf-to-star
ratio, shifting it closer to values found in some star forming regions.
