These are galaxies of the Hercules Cluster [ http://www.astr.ua.edu/gifimages/hercules.html ], an archipelago of "island universes" [ http://www.physics.rutgers.edu/~sellwood/lectures/notes18.html ] a mere 650 million light-years distant. This cluster is loaded with gas and dust rich, star forming, spiral galaxies [ http://antwrp.gsfc.nasa.gov/apod/ap970726.html ] but has relatively few elliptical galaxies [ http://antwrp.gsfc.nasa.gov/apod/ap961106.html ], which lack gas and dust and the associated newborn stars [ http://antwrp.gsfc.nasa.gov/apod/ap980411.html ]. Colors in the composite image show the star forming galaxies with a blue tint and ellipticals with a slightly yellowish cast. In this cosmic vista many galaxies seem to be colliding [ http://antwrp.gsfc.nasa.gov/apod/ap971027.html ] or merging [ http://www.astr.ua.edu/pairs2.html ] while others seem distorted - clear evidence that cluster galaxies [ http://www-xray.ast.cam.ac.uk/oday/clusters_demo.html ] commonly interact. Over time, the galaxy interactions are likely to affect the the content of the cluster [ http://www-xray.ast.cam.ac.uk/oday/clusters_composition.html ] itself. Researchers believe that the Hercules [ http://www.astro.wisc.edu/~dolan/constellations/constellations/ Hercules.html ] Cluster [ http://crux.astr.ua.edu/white/mug/cluster/clusters.html ] is significantly similar to young galaxy clusters [ http://antwrp.gsfc.nasa.gov/apod/ap980821.html ] in the distant, early Universe and that exploring galaxy types and their interactions in nearby Hercules will help unravel the threads of galaxy [ ftp://crux.astr.ua.edu/web/goodies/data_resources/galaxies.text ] and cluster evolution [ http://oposite.stsci.edu/pubinfo/background-text/galaxpdx.txt ].
Dr. Victor Andersen [ http://crux.astr.ua.edu/~andersen/home.html ] ( University of Alabama [ http://crux.astr.ua.edu/AstroHome.html ], KPNO [ http://www.noao.edu/kpno/kpno.html ]) Courtesy W. Keel [ mailto:email@example.com ]