The open cluster Stephenson 2 was discovered by American astronomer Charles Bruce Stephenson in 1990 in the data obtained by a deep infrared survey.

The brightest star in the region of the cluster was given the identifier 1 in the first analysis of cluster member properties.
 However, it was not considered to be a member of Stephenson 2 due to its outlying position, abnormally high brightness, and slightly atypical proper motion.
 In a later study, the same star was given the number 18 and assigned to an outlying group of stars called Stephenson 2 SW, assumed to be at the same distance as the core cluster.
The open cluster Stephenson 2 was discovered by American astronomer Charles Bruce Stephenson in 1990 in the data obtained by a deep infrared survey.
The brightest star in the region of the cluster was given the identifier 1 in the first analysis of cluster member properties.  However, it was not considered to be a member of Stephenson 2 due to its outlying position, abnormally high brightness, and slightly atypical proper motion.  In a later study, the same star was given the number 18 and assigned to an outlying group of stars called Stephenson 2 SW, assumed to be at the same distance as the core cluster.
Stephenson 2-18