Tags: Star.
Westerlund 2 is a young massive obscured star cluster with an estimated age of about one or two million years. It contains some of the hottest brightest and most massive stars known. The cluster contains a dozen of O stars of which at least three are eclipsing binaries many pre–main sequence stars and two Wolf-Rayet Stars: the binary WR20a and the single star WR20b all of spectral type WN6ha. They are probably not actually Wolf-Rayet stars i.e.
