大熊座移動星群
In 2006, a new nearby star cluster was discovered associated with the 4th magnitude star Mu Ophiuchi. The Mamajek 2 cluster appears to be a poor cluster remnant analogous to the Ursa Major Moving Group, but 7 times more distant (approximately 170 parsecs away). Mamajek 2 appears to have formed in the same star-forming complex as the NGC 2516 cluster roughly 135 million years ago.