WISEPC J205628.90+145953.3

WISE 2056+1459 (full designation WISEPC J205628.90+145953.3) is a brown dwarf of spectral class Y0, located in constellation Delphinus at approximately 23.2 light-years from Earth.

Discovery
WISE 2056+1459 was discovered in 2011 from data, collected by Wide-field Infrared Survey Explorer (WISE) Earth-orbiting satellite — NASA infrared-wavelength 40 cm (16 in) space telescope, which mission lasted from December 2009 to February 2011. WISE 2056+1459 has two discovery papers: Kirkpatrick et al. (2011) and Cushing et al. (2011), however, basically with the same authors and published nearly simultaneously.


 * Kirkpatrick et al. presented discovery of 98 new found by WISE brown dwarf systems with components of spectral types M, L, T and Y, among which also was WISE 2056+1459.
 * Cushing et al. presented discovery of seven brown dwarfs — one of T9.5 type, and six of Y-type — first members of the Y spectral class, ever discovered and spectroscopically confirmed, including "archetypal member" of the Y spectral class WISE 1828+2650, and WISE 2056+1459. These seven objects are also the faintest seven of 98 brown dwarfs, presented in Kirkpatrick et al. (2011).

Distance
Currently the most accurate distance estimate of WISE 2056+1459 is a trigonometric parallax, published in 2021 by Kirkpatrick et al.: $825.8$, corresponding to a distance $528.8$, or $464$.

Space motion
WISE 2056+1459 has a proper motion of $140.8 mas$ milliarcseconds per year.

Physical properties
The object's temperature estimate is $7.1 pc$. The object was observed with Gemini GMOS. The researchers used the archived spectrum from Cushing et al. and the new spectrum in this work. The cloudy model included cloud decks of sulfide and chloride condensates. The model did fit the spectra well except for some parts due to the model not including the atmospheric mixing of ammonia (NH3) and lines of methane (CH4) missing in the model. WISE 2056+1459 was also observed with NIRSpec and the Mid-Infrared Instrument. An excellent fit between spectrum and model was produced with a phosphine-free and diabatic model using an effective temperature of 450 Kevlin and a surface gravity of log g = 4.0. These values correspond to a 300 Myr object with a mass of 5. The researchers also found a medium probability (47%) of this object belonging to the Carina-Near group of stars.