2MASS J10475385+2124234

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.

The object first attracted attention by becoming the first brown dwarf of spectral class T from which radio waves were detected.

Follow-up observations with the Keck I 10-meter telescope's Near Infrared Camera (NIRC) were conducted on 27 May 1999 and identified methane in 2MASS J1047+21's near-infrared spectrum, classifying it as a T-type brown dwarf.

The wind speed is directly inferred from minute, regular cycles in its visible (which matches its ultra-violet) appearance compared to the same at radio wave spectra.

[10] The visible and infrared (IR) data, on the other hand, reveal what's happening in the gas giant's cloud tops.

Artist's impression of a brown dwarf and its magnetic field
Artist's concept of the interior structure of a brown dwarf. The magnetic field rotates at a different rate than the top of the atmosphere.