2MASS J0523−1403 has a luminosity of 0.000126 L☉, a radius of 0.086 R☉, and an effective temperature of 2074 K. These values are currently the lowest known for a main sequence star.[2] It has a stellar classification of L2.5 and a V-K color index of 9.42.[2] The mass is calculated to be 67.54±12.79 MJ (0.0644±0.0122 M☉).[2] Observation with the Hubble Space Telescope has detected no companion beyond 0.15 arcsecond.[8] Sporadic radio emissions were detected by the VLA in 2004.[9] H-alpha (Hα) emissions have also been detected, a sign of chromospheric activity.[5]