WISE J2209+2711 (WISE J220905.73+271143.9) is a brown dwarf of spectral type Y0:, located in constellation Pegasus at 22 light-years from Earth. Its discovery was published in 2014 by Cushing et al.

Physical properties

WISE J2209+2711 is one of a few Y-dwarfs observed with the NIRSpec and MIRI instruments aboard the James Webb Space Telescope. The modelling re-produced the spectrum with an excellent fit using phosphine-free and diabatic models. The excellent fit was achieved with a model that used an effective temperature of 350 K (77 °C; 170 °F) and a surface gravity of 104 cgs. This corresponds to a 5 MJ object with an age of 800 Myr. An atmospherical retrieval of WISE J2209+1711's spectral energy distribution, colleted by JWST's NIRSpec and MIRI instruments, derive a mass of 9 MJ, a radius of 1.06 RJ, an effective temperature of 350 K (77 °C; 170 °F) and a surface gravity of 104.28 cgs. The position of WISE J2209+2711 in the surface gravity-temperature diagram indicates an age close to two Gyr.

See also