The Rosette Nebula is a star-forming region about 5,000 light years from Earth. A recent Chandra study of the cluster named NGC 2237, provides the first probe of the low-mass stars in this satellite cluster. Previously only 36 young stars had been discovered in NGC 2237, but the Chandra work has increased this sample to about 160 stars. The presence of several X-ray emitting stars around the pillars and the detection of an outflow, commonly associated with very young stars, originating from a dark area of the optical image indicates that star formation is continuing in NGC 2237. By combining these results with earlier studies, the scientists conclude that the central cluster formed first, followed by expansion of the nebula, which triggered the formation of the neighboring clusters, including NGC 2237. Release date September 8, 2010.