武仙星系团

2020年11月7日 The Hercules Cluster of Galaxies Image Credit & Copyright: Howard Trottier Explanation: These are galaxies of the Hercules Cluster, an archipelago of island universes a mere 500 million light-years away. Also known as Abell 2151, this cluster is loaded with gas and dust rich, star-forming spiral galaxies but has relatively few elliptical galaxies, which lack gas and dust and the associated newborn stars. The colors in this deep composite image clearly show the star forming galaxies with a blue tint and galaxies with older stellar populations with a yellowish cast. The sharp picture spans about 1/2 degree across the cluster center, corresponding to over 4 million light-years at the cluster’s estimated distance. Diffraction spikes around brighter foreground stars in our own Milky Way galaxy…