It is a Y-dwarf, meaning it is one of the coldest directly imaged astronomical objects.

[1] It was discovered in 2015, using the Wide-field Infrared Survey Explorer and spectroscopy from the Hubble Space Telescope.

The authors find that the J-band peak in the spectrum is narrower than the Y0 standard and therefore assigned a spectral type of Y1, with an estimated temperature of 300−400 Kelvin.

[4] Near-infrared photometry was later obtained with Hubble and a temperature of 335 ±11 K and a mass of 11 ±3 MJ was estimated.

[2] WISE 2354+0240 was observed with the JWST and the temperature was estimated to be 362+10−12 K. The object is not described in detail in this work.