DISCOVERY OF THE WIDEST VERY LOW MASS FIELD BINARY

We present the discovery of the widest (similar to 6700 AU) very low mass (VLM) field binary to date, found in a proper motion cross-match of the Sloan Digital Sky Survey and the Two Micron All Sky Survey. Our follow-up J-band imaging provides a 10 year baseline for measuring proper motions. Consequently, we are able to confirm the common proper motion of the pair to within 10 mas, implying a 99.5% probability of their physical association. Near-infrared spectra of the components indicate spectral types of M6 +/- 1 and M7 +/- 1. The system resides at a spectroscopic distance of 105 +/- 13 pc and has an angular separation of 63 ''.38 +/- 0 ''.05. We have used evolutionary models to infer component masses of 0.105(-0.017)(+0.029) M-circle dot 0.091(-0.007)(+0.010) M-circle dot. The large separation and low binding energy of this system can provide constraints for formation models of VLM stars.