2MASS J10475385+2124234 (abbreviated to 2MASS J1047+21) is a brown dwarf of spectral class T6.5, in the constellation Leo about 34 light-years from Earth, hence in galactic topographical and interstellar medium study terms being in the Local Bubble and very nearby in the Orion Arm. It is the first brown dwarf to have an inferred range of its typical wind speeds computed.