UGPS J072227.51−054031.2 (designation often abbreviated to UGPS 0722−05) is a
brown dwarf of late T type, or possibly a
rogue planet located approximately from Earth.
History of observations
Discovery
The
astronomical object
An astronomical object, celestial object, stellar object or heavenly body is a naturally occurring physical entity, association, or structure that exists in the observable universe. In astronomy, the terms ''object'' and ''body'' are often us ...
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
Proper motion is the astrometric measure of the observed changes in the apparent places of stars or other celestial objects in the sky, as seen from the center of mass of the Solar System, compared to the abstract background of the more dista ...
on 2 March 2010. The reported distance is derived from the current measured
parallax
Parallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight and is measured by the angle or semi-angle of inclination between those two lines. Due to foreshortening, nearby objects ...
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 parsecs.
Space motion
UGPS 0722−05 has proper motion of about 970 milliarcseconds per year.
Radial velocity
The radial velocity or line-of-sight velocity, also known as radial speed or range rate, of a target with respect to an observer is the temporal rate of change, rate of change of the distance or Slant range, range between the two points. It is e ...
of UGPS 0722-05, measured by Bochanski ''et al.'' and published in 2011, is 46.9 ± 2.5 km/s.
[Positive value of radial velocity indicates that UGPS 0722−05 currently moves away from us. A significant excess of radial velocity (46.9 km/s) over tangential velocity (19 km/s) indicates that UGPS 0722-05 was much closer to us in past (assuming proper motion and parallax from Leggett ''et al.'' (2012), minimal distance from Solar system to UGPS 0722-05 was 5.0 ly about 72000 BC, and probably it was one of the nearest Solar neighbors at the time).]
Properties
The object is roughly the volume of
Jupiter, but is estimated to have 5–40
Jupiter masses (). This would make it less massive than
ε Indi Ba. Planets have a mass of less than about 13
Jupiter masses.
Infrared spectra
Infrared spectroscopy (IR spectroscopy or vibrational spectroscopy) is the measurement of the interaction of infrared radiation with matter by absorption, emission, or reflection. It is used to study and identify chemical substances or functional ...
shows the object contains water vapor and
methane and has a surface temperature of approximately 480–560
kelvins.
Notes
References
External links
Article on UGPS 0722-05 at SolStation.com
{{DEFAULTSORT:UGPS J0722-0540
Local Bubble
Monoceros (constellation)
Brown dwarfs
UGPS objects
T-type stars
Rogue planets