  We report the discovery of LSR0602+3910, an L dwarf of class L1. The object
was initially identified by Lepine et al. (2002) as a new high proper motion
star lying close to the Galactic plane. Its 2MASS J-K_s=1.43 is consistent with
an L dwarf, which we now confirm spectroscopically. In addition, we see a
signature of Li I absorption, making LSR0602+3910 a brown dwarf, one of the
brightest known (K_s=10.86). Among L dwarfs it is second in brightness to the
combined light of 2MASS 0746+20, a close binary system. We see no indication
that LSR0602+3910 is a binary, although high-resolution imaging will be
required to confirm this. Spectroscopic and photometric distance estimates
agree very well, placing LSR0602+3910 at d=10.6+-0.8 pc. LSR0602+3910 was most
likely missed in previous searches because of its proximity to the plane, the
region that most searches avoided. We estimate that some 40% of bright L dwarfs
are missed because of this selection effect.
