NGC 2129 is an open cluster in the constellation Gemini. It has an angular distance of 2.5 arcminutes and is approximately 2.2 ± 0.2 kpc (~7,200 light years) from the Sun inside the Local spiral arm. At that distance, the angular size of the cluster corresponds to a diameter of about 10.4 light years. NGC 2129 is a very young cluster whose age has been estimated at 10 million years.
The group is dominated by two close B-Type stars, HD 250289 (B2III) and HD 250290 (B3I). With the two stars sharing the same proper motion and radial velocity it is likely that the two constitute a binary system.
See also
List of Messier objects
List of NGC objects
List of open clusters
General Catalogue of Nebulae and Clusters
References
External links
NASA/IPAC Extragalactic Database (NED): NGC 2129
Open clusters
Gemini (constellation) 2129