AB Doradus Moving Group

AB Doradus Moving Group is a group of about 30 associated stars that are moving through space together with the star AB Doradus. A moving group is distinguished by its members having about the same age, composition (or metallicity) and motion through space. Hence they most likely formed in the same location.

This group is located about 20 parsecs from the Earth and is the closest known co-moving group. It has estimated age of either 50 million or 119 million years. The average space velocity of this group has components of U = −8, V = −27 and W = −14 km/s. About 10 of these stars form a nuclear group within a volume roughly 10 parsecs across.

The proximity of this moving group makes it useful for studies of shared stellar properties, as well as detection of companions through direct imaging. These can be used for refinement of young stellar models, for example.

In 2012, a group of astronomers announced the discovery of CFBDSIR 2149-0403, a free-floating planet between 4 and 7 times the mass of Jupiter that appeared to be part of the moving group. At the time of its discovery, it was the closest known rogue planet; there are a few other previously detected objects which might also be rogue planets, but astronomers are uncertain as to whether they are planets or brown dwarfs because their ages are unknown. These previous discoveries were discussed in the research paper in which CFBDSIR 2149-0403 was announced.