... The Hercules Cluster of Galaxies . ... 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. ... Boasting no bright stars, it blends inconspicuously with the starry southern sky. ... Connecting the Pipe Nebula to the colorful regon near bright star Antares is a dark cloud dubbed the Dark River, flowing from the picture's left edge. ...