  We present the discovery of the widest known ultracool dwarf - white dwarf
binary. This binary is the first spectroscopically confirmed widely separated
system from our target sample. We have used the 2MASS and SuperCOSMOS archives
in the southern hemisphere, searching for very widely separated ultracool dwarf
- white dwarf dwarf binaries, and find one common proper motion system, with a
separation of 3650-5250AU at an estimated distance of 41-59pc, making it the
widest known system of this type. Spectroscopy reveals 2MASS J0030-3740 is a DA
white dwarf with Teff=7600+/-100K, log(g)=7.79-8.09 and M(WD)=0.48-0.65Msun. We
spectroscopically type the ultracool dwarf companion (2MASS J0030-3739) as
M9+/-1 and estimate a mass of 0.07-0.08Msun, Teff=2000-2400K and
log(g)=5.30-5.35, placing it near the mass limit for brown dwarfs. We estimate
the age of the system to be >1.94Gyrs (from the white dwarf cooling age and the
likely length of the main sequence lifetime of the progenitor) and suggest that
this system and other such wide binaries can be used as benchmark ultracool
dwarfs.
