AAO image reference AAT 119. « Previous || Next »
Top left is NE. Image width is about 12 arc min
Image and text © 2001-2010, Australian Astronomical Observatory, photograph by David Malin.
Globular clusters are among the oldest objects known. The stars within them seem to contain much less of the 'metals' that are found in other stars, and since the universe was almost completely metal-free (i.e. contained only hydrogen and helium) in the beginning, it seems that globular cluster stars were among the first stellar objects to form. However, it is certain these beautiful, compact cities of stars did not look like this in their youth, when they would have been much brighter, their light dominated by hot massive stars that have vanished.
This particular globular cluster is in the deep southern sky in Vela and is at a distance of about 15,000 light years. The colours of the stars are subtle but this picture clearly shows the cool but bright red giant stars whose light dominates the cluster. The cluster is seen quite cose to the galactic plane, so its light is slightly reddened by intervening dust.
For details of photographic exposure, search technical table by AAT reference number.