Life Cycle of Stars
This one picture of the giant galactic nebula NGC 3603 captures various stages in the life cycle of stars. Upper right of center, for example, is the evolved blue supergiant Sher 25, with a ring of glowing gas. Near the center is a so-called starburst cluster dominated by younger, hot stars whose ionizing radiation and high-speed "winds" have blown a large cavity around them. (These violent emissions have also sculpted giant gaseous pillars from the cold molecular-hydrogen cloud.) The dark clouds at upper right are believed to represent an even earlier stage of star formation.
Photo by Wolfgang Brandner (JPL/IPAC), Eva K. Grebel (University of Washington), You-Hua Chu (University Illinois Urbana-Champaign) and NASA.