THE CONTRIBUTION OF BROWN DWARFS TO THE LOCAL MASS BUDGET OF THE GALAXY

Based on the recent discoveries of free floating brown dwarfs we deriv e estimates of the local mass density of this population of objects. M ass density estimates from various surveys span the range 0.03 to 0.00 5 M. pc(-3). These estimates are compared with the local mass densitie s of the other constituents of the galactic disk and, in particular, w ith the dynamically determined total local mass density. We argue that brown dwarfs might indeed contribute significantly to the local mass budget, but that a local mass density as high as 0.03 M. pc(-3) as sug gested by Ruiz et al. (1997) is rather unlikely.