The ground-based image in visible light locates the hub area imaged with the Hubble Space Telescope. This barred galaxy feeds material into its hub igniting star birth. The Hubble NICMOS instrument penetrating beneath the dust reveals clusters of young stars.
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.