October 6, 1999: The Hubble telescope is uncovering important new clues to a galaxy's birth and growth by peering into its heart — a bulge of millions of stars resembling a bulbous center yolk in the middle of a disk of egg white.
Astronomers have combined information from the Hubble telescope's visible- and infrared-light cameras to show the heart of four spiral galaxies peppered with ancient populations of stars. The top row of pictures, taken by a ground-based telescope, represents complete views of each galaxy. The blue boxes outline the regions observed by the Hubble telescope. The bottom row represents composite pictures from Hubble's visible- and infrared-light cameras. Astronomers combined views from both cameras to obtain the true ages of the stars surrounding each galaxy's bulge. The Hubble telescope's sharper resolution allows astronomers to study the intricate structure of a galaxy's central region.See the rest:
PRC99-34a Credits: Credits for the ground-based image: Allan Sandage (The Observatories of the Carnegie Institution of Washington) and John Bedke (Computer Sciences Corporation and the Space Telescope Science Institute) Credits for the WFPC2 image: NASA and John Trauger (Jet Propulsion Laboratory) Credits for the NICMOS image: NASA, ESA, and C. Marcella Carollo (Johns Hopkins University and Columbia University)
PRC99-34b Credits: Credits for the ground-based images: Allan Sandage (The Observatories of the Carnegie Institution of Washington) and John Bedke (Computer Sciences Corporation and the Space Telescope Science Institute) Credits for WFPC2 and NICMOS composites: NASA, ESA, and Reynier Peletier (University of Nottingham, United Kingdom)