The centre of the Omega Centauri globular cluster, photographed in UV light by the Ultraviolet Imaging Telescope (UIT), part of the ASTRO-1 payload of Shuttle Columbia's STS-35 mission of 2-11 December 1990. Placing the UIT in space has allowed the first clear image of this cluster to be made in UV light. Many sources were seen which are invisible to land-based optical telescopes, including many 'horizontal branch' stars. These are small, hot stars which are the remnants of red giants that have ejected most of their material, but which were not large enough to form supernovae. This photograph was taken at an effective wavlength of 160 nm.