CFBDSIR 2149−0403
CFBDSIR 2149-0403 is a free-floating planetary-mass object or possibly a high-metallicity, low-mass brown dwarf in the constellation Aquarius. Originally, it was thought to be part of the AB Doradus moving group as indicated by its position and proper motion, but the same team that discovered the object and conjectured its membership in the group has now rejected that hypothesis due to newer measurements. Without that membership, the age and mass of the object cannot be constrained.
Discovery
CFBDSIR 2149-0403 was discovered by the Canada-France Brown Dwarfs Survey, a near-infrared sky survey, and confirmed by WISE data. Philippe Delorme, of the Institute of Planetology and Astrophysics of Grenoble in France and his team, including researchers at Université de Montréal in Canada, detected CFBDSIR2149's infrared signature using the Canada-France-Hawaii Telescope. They then examined the body's properties with the European Southern Observatory's Very Large Telescope in Chile.Distance
If this object is actually a rogue planet, then it is among the closest that has ever been spotted. An estimate assuming it to be part of the AB Doradus moving group would result in a distance of from Earth.In 2016, a parallax measurement of CFBDSIR 2149-0403 resulted in a distance of .
Age and characteristics
In the discovery paper, CFBDSIR 2149-0403 was claimed to possibly be a kinematic member of the AB Doradus moving group. The ABDMG appears to be similar in age to the Pleiades, which has a lithium-depletion boundary age of Myr. If so, this object would be likely a free-floating planet with a mass lower than the limit for deuterium burning.However, a subsequent analysis by the discoverers ruled out the possibility that it is part of this moving group. Therefore, there is no way to constrain its mass and status unless assuming age values; estimates are either under 500 million years as a rogue planet with mass between 2 and 13 Jupiter masses, or else a two- to three-billion-year-old brown dwarf with mass between 2 and 40 Jupiter masses. The object shows signs of low gravity, which could be attributable to youth.
Spectroscopic observations give CBFDSIR 1428+10 a spectral type of T7, classifying it as a late T dwarf.