SIMBAD references

We report the discovery of a single-lined spectroscopic binary with an ultracool dwarf (UCD) primary with a spectral type between M8 and L0.5. This system was discovered during the course of an ongoing survey to monitor L dwarfs for radial velocity variations and is the first known small-separation (a<1 AU) spectroscopic binary among dwarfs at the M/L transition. Based on radial velocity measurements with a typical precision of 300 m/s, we estimate the orbital parameters of this system to be P=246.73±0.49 days, a₁sini=0.159±0.003 AU, and M₂sini=0.2062(M₁+M₂)^2/3±0.0034 M_☉. Assuming a primary mass of M₁=0.08 M_☉(based on spectral type), we estimate the secondary minimum mass to be M₂sini=0.054 M_☉. With future photometric, spectroscopic, and interferometric observations it may be possible to determine the dynamical masses of both components directly, making this system one of the best-characterized UCD binaries known.