Chandra Release - January 23, 2008

Visual Description: Westerlund 2

This star cluster is called Westerlund 2 and is shown in X-ray light.  The colors include clouds of deep purple and magenta, with many tiny dots of gold and blue, and some of red.  It resembles a large cluster of multicolored stars in the center, with 5 or 6 loose “arms” of purple gas extending out. This Chandra image of Westerlund 2 depicts low energy X-rays in red, intermediate energy X-rays in green, and high energy X-rays in blue. The object is a very high density of massive stars that are bright in X-rays, plus the diffuse X-ray emission.  An incredibly massive double star system called WR20a is visible as a bright yellow point just below and to the right of the cluster's center. This system contains stars with masses of 82 and 83 times that of the Sun.