H/T Lana Duze M25, blue splashes. Many stars like our Sun were formed in open clusters. Open cluster, M25, the constellation of the Archer (Sagittarius), contains thousands of stars and is about two thousand light years distant. The stars in this cluster all formed together about 90 million years ago. The bright young stars in M25 appear blue. Open clusters, also called galactic clusters, contain fewer and younger stars than globular clusters. Also unlike globular clusters, open clusters are generally confined to the plane of our Galaxy. Like many Messier objects, this one was known since earlier times, discovered in 1745 by Jean-Philippe Loys de Chéseaux. Much like the Pleiades, this is a young star cluster, with an estimated age of just 90 million years! But unlike the Pleiades, which is just a few hundred light years away, M25 is over 2,000 light years distant! A close look at this cluster shows two large, bright red-colored stars, two large, bright whitish-yellow colored stars, and then a spattering of bright, blue stars of different magnitudes. You can also see just a hint of nebulosity — or dust — present across the cluster.
Posted on: Fri, 05 Sep 2014 15:18:01 +0000