CFBDSIR 2149-0403

CFBDSIR 2149-0403 (full designation CFBDSIR J214947.2-040308.9) is a free-floating planetary-mass object or possibly a low-mass brown dwarf, likely part of the AB Doradus moving group (ABDMG) as indicated by its position and proper motion. There is insufficient evidence to demonstrate that CFBDSIR 2149-0403 formed as a planet and was subsequently ejected. Although there have been candidates for objects like this reported before, it is the first such object with a spectroscopically confirmed low age and an upper limit on its estimated mass below 13 Jupiter masses. It must be noted that the estimation of its mass rely on its suspected membership in AB Doradus (which provides a distance and an age), as well as on the current generation of brown dwarfs evolutionary models. It is thus by no means a direct mass measurement.

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, 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 (which has not been decisively demonstrated), then it is among the closest that has ever been spotted. If the object belongs to the ABDMG then its distance is estimated to be 40±4 parsecs (130±13 light years) from Earth; other possible estimates range from 25 to 50 parsecs. A possibly closer candidate is PSO J318.5-22.

Age
In the discovery paper, CFBDSIR 2149-0403 was claimed to possibly be a kinematic member of the AB Doradus Moving Group. The AB Doradus Moving Group appears to be similar in age to the Pleiades, which has a lithium-depletion boundary age of 130±20 Myr.[6] If CFBDSIR2149 is indeed associated with the AB Doradus Moving Group—which it is with 90 percent probability—then it is similarly young. It also shows signs of low gravity (brighter K band in the near-infrared), which is attributable to youth.

Atmosphere
Spectroscopy observations have found absorption by gaseous methane and water.