Luminosity (bolometric) (6.3 ± 0.4×10 L☉ Constellation Monoceros | Magnitude 24.32 | |
Similar SCR 1845‑6357, DEN 1048−3956, WISE 1506+7027, LHS 292, DX Cancri | ||
UGPS J072227.51-054031.2 (designation often abbreviated to UGPS 0722-05) is a brown dwarf of late T type, located approximately 4.1 parsecs (13 light-years) from Earth.
Contents
Discovery
The astronomical object was discovered by Philip Lucas at the University of Hertfordshire and announced in 2010. The discovery image was taken on 28 November 2006 by the UKIRT Infrared Deep Sky Survey (UKIDSS) with a recovery image confirming the object's proper motion on 2 March 2010. The reported distance is derived from the current measured parallax of 246 milliarcseconds. The object was initially reported to be at an even closer distance of 2.9 parsecs, which would have placed it among the ten nearest stars to the Sun but later measurements revealed that the object was in fact located at a greater distance than initially thought, at 4.1+0.6
−0.5 parsecs.
Adaptive optics observations
In 2010 Bouy et al. observed UGPS 0722-05 using adaptive optics at the Very Large Telescope. Any companion with H magnitude ≲ 19.4 at separations larger than 50 mas, or with H magnitude ≲ 21.4 at separations larger than 100 mas was not detected.
Assignment of spectral class
In 2010 Lucas et al. provisionally assigned to UGPS 0722-05 spectral class T10 and suggested that it may be the first example of a new spectral class.
In 2011 paper Cushing et al. established a boundary between spectral class T and new spectral class Y—a feature of spectrum, associated with NH3, and introduced spectral standards at the T/Y transition—for classes T9 and Y0. UGPS 0722-05 was reclassified to T9, and was declared the T9 spectral standard.
Distance
Currently the most accurate distance estimate of UGPS 0722-05 is a trigonometric parallax, published in 2013 by Leggett et al.: 0.2428 ± 0.0024 arcsecond, corresponding to a distance 4.12 ± 0.04 pc, or 13.43 ± 0.13 ly.
Space motion
UGPS 0722-05 has proper motion of about 970 milliarcseconds per year.
Radial velocity of UGPS 0722-05, measured by Bochanski et al. and published in 2011, is 46.9 ± 2.5 km/s.
Properties
The object is roughly the volume of Jupiter, but is estimated to have 5–40 Jupiter masses (MJ). This would make it less massive than ε Indi Ba. Planets have a mass of less than about 13 Jupiter masses. Infrared spectra shows the object contains water vapor and methane and has a surface temperature of approximately 480–560 Kelvin.