2MASS J00361617+1821104 (abbreviated to 2MASS 0036+1821) is a brown dwarf, located in 28.6 light-years from Earth in the constellation Pisces.

[5] 2MASS 0036+1821 is of spectral type L3.5, the surface temperature is 1300-2000 Kelvin.

Its position shifts due to its proper motion by 0.9071 arcseconds per year.

The surface of 2MASS 0036+1821 is completely covered by clouds, although cloud deck appear to be thin (less than ten optical depths)[4] Because of unusually rapid rotation, it is possessing a strong magnetic field over 1000 G at the photosphere level,[6] and is well known for its radio emissions.

Assuming an age of 0.5-5 Billion years, the A component has a mass estimate of 51-76 MJ and the B component has a mass estimate of 47-74 MJ.