WISE 1828+2650


WISE 1828+2650 is a brown dwarf or rogue planet of spectral class >Y2, located in constellation Lyra at approximately 47 light-years from Earth. It is the "archetypal member" of the Y spectral class.

History of observations

Discovery

WISE 1828+2650 was discovered in 2011 from data collected by NASA's 40 cm Wide-field Infrared Survey Explorer space telescope at infrared wavelength. WISE 1828+2650 has two discovery papers: Kirkpatrick et al. and Cushing et al., however, basically with the same authors and published nearly simultaneously.
Currently the most accurate distance estimate of WISE 1828+2650 is a trigonometric parallax, measured using Spitzer Space Telescope and published in 2013 by Trent Dupuy and Adam Kraus: 0.070 ± 0.014 arcsec, corresponding to a distance 14.3 pc, or 46.6 ly.

Proper motion

WISE 1828+2650 has proper motion of about 966 milliarcseconds per year.

Physical properties

Until the discovery of WISE 0855−0714 in 2014 WISE 1828+2650 was considered as the coldest currently known brown dwarf or the first example of free-floating planet. It has a temperature in the range and was initially estimated below 300 K, or about. It has been assigned the latest known spectral class.
The mass of WISE 1828+2650 is in the range for ages of 0.1–10 Gyr.
High tangential velocity of WISE 1828+2650, characteristic of an old disk population, indicates possible age of WISE 1828+2650 in the range 2–4 Gyr, leading to mass estimate of about.
WISE 1828+2650 is similar in appearance to the other Y-type object WD 0806-661 B. WD 0806-661 B could have formed as a planet close to its primary, WD 0806-661 A, and later, when the primary became a white dwarf and lost most of its mass, have migrated into a larger orbit of 2500 AU, and similarity between WD 0806-661 B and WISE 1828+2650 may indicate that WISE 1828+2650 had formed in the same way.

Possible binarity

Comparison between WISE 1828+2650 and WD 0806-661 B may suggest that WISE 1828+2650 is a system of two equal-mass objects. Observations with Hubble Space Telescope and Keck-II LGS-AO system had not revealed binarity, suggesting that if any such companion exists, it would have an orbit less than 0.5 AU, and no evidence for binarity yet exists.

Comparison