  We report observations obtained with the Keck adaptive optics facility of the
nearby (d=9.8 pc) binary Gl~569. The system was known to be composed of a cool
primary (dM2) and a very cool secondary (dM8.5) with a separation of 5" (49
Astronomical Units). We have found that Gl~569~B is itself double with a
separation of only 0".101$\pm$0".002 (1 Astronomical Unit). This detection
demonstrates the superb spatial resolution that can be achieved with adaptive
optics at Keck. The difference in brightness between Gl~569~B and the companion
is $\sim$0.5 magnitudes in the J, H and K' bands. Thus, both objects have
similarly red colors and very likely constitute a very low-mass binary system.
For reasonable assumptions about the age (0.12~Gyr--1.0~Gyr) and total mass of
the system (0.09~M$_\odot$--0.15~M$_\odot$), we estimate that the orbital
period is $\sim$3 years. Follow-up observations will allow us to obtain an
astrometric orbit solution and will yield direct dynamical masses that can
constrain evolutionary models of very low-mass stars and brown dwarfs.
