This page is a candidate for deletion. The reason given is: copied from another source and only made because of inaccurate size Stephenson 2-18 is a Star that is in the constellation of Scutum within the Star cluster of Stephenson 2. It is 19,570 light-years away from the Earth, near the supermassive black hole named Sagittarius A*.
Observation history[]
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 cluster is also known as RSGC2, one of several massive open clusters in Scutum, each containing multiple red supergiants.
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 a similar distance to the core cluster. The designation St2-18 (short for Stephenson 2-18) is often used for the star, following the numbering from Deguchi (2010). To reduce confusion from using the same number for different stars and different numbers for the same star, designations from Davis (2007) are often given a prefix of DFK or D, for example Stephenson 2 DFK 1.