Wide-field image of the NGC 2808 region (ground-based image): The globular cluster NGC 2808 as seen in the Digitized Sky Survey 2 (DSS2). The image is a colour composite from DSS2 images, the field of view is 2.7x2.8 degrees.

Name: NGC 2808
Type: Milky Way : Star : Grouping : Cluster : Globular
Category: Star Clusters
Constellation: Carina
Distance: 30000 light years
Release date: 2 May 2007, 15:00
Credit: Davide De Martin (ESA/Hubble), the ESA/ESO/NASA Photoshop FITS Liberator & Digitized Sky Survey 2

The southern Milky Way (ground-based image): Wide-field image of the southern Milky Way. On the right is the constellation of Orion, on the left, Carina, the Keel, where NGC 2808 is located.

Name: NGC 2808
Type: Solar System : Sky Phenomenon : Night Sky : Milky WayMilky Way : Star : Grouping : Cluster : Globular
Category: Star Clusters
Distance: 30000 light years
Release date: 2 May 2007, 15:00
Credit: A. Fujii

Dark matter ring in galaxy cluster Cl 0024+17 (ZwCl 0024+1652): This Hubble Space Telescope composite image shows a ghostly "ring" of dark matter in the galaxy cluster ZwCl0024+1652. The ring-like structure is evident in the blue map of the cluster's dark matter distribution. The map is superimposed on a Hubble image of the cluster. The ring is one of the strongest pieces of evidence to date for the existence of dark matter, an unknown substance that pervades the Universe. The map was derived from Hubble observations of how the gravity of the cluster ZwCl0024+1652 distorts the light of more distant galaxies, an optical illusion called gravitational lensing. Although astronomers cannot see dark matter, they can infer its existence by mapping the distorted shapes of the background galaxies. The mapping also shows how dark matter is distributed in the cluster. Astronomers suggest that the dark-matter ring was produced from a collision between two gigantic clusters. Dark matter makes up the bulk of the Universe's material and is believed to make up the underlying structure of the cosmos. The Hubble observations were taken in November 2004 by the Advanced Camera for Surveys (ACS). Thanks to the exquisite resolution of the ACS, astronomers saw the detailed cobweb tracery of gravitational lensing in the cluster.

Name: ZwCl0024+1652
Type: Early Universe : Galaxy : Grouping : ClusterEarly Universe : Cosmology : Phenomenon : Dark Matter
Category: CosmologyGalaxies
Constellation: Pisces
Distance: z=0.39 (redshift)
Release date: 15 May 2007, 19:00
Credit: NASA, ESA, M.J. Jee and H. Ford (Johns Hopkins University)

Hubble finds dark matter ring in galaxy cluster: An international team of astronomers using the NASA/ESA Hubble Space Telescope has discovered a ghostly ring of dark matter that was formed long ago during a titanic collision between two massive galaxy clusters. It is the first time that a dark matter distribution has been found that differs substantially from the distribution of ordinary matter. This image shows the galaxy cluster Cl 0024+17 (ZwCl 0024+1652) as seen by Hubble's Advanced Camera for Surveys. The image displays faint faraway background galaxies that had their light bent by the cluster's strong gravitational field. By mapping the distorted light and using it to deduce how dark matter is distributed in the cluster, astronomers spotted the ring of dark matter. One of the background galaxies is located about two times further away than the yellow cluster galaxies in the foreground, and has been multiple-imaged into five separate arc-shaped components, seen in blue.

Name: ZwCl0024+1652
Type: Early Universe : Galaxy : Grouping : ClusterEarly Universe : Cosmology : Phenomenon : Dark Matter
Category: Cosmology
Constellation: Pisces
Distance: z=0.39 (redshift)
Release date: 15 May 2007, 19:00
Credit: NASA, ESA, M.J. Jee and H. Ford (Johns Hopkins University)

Wide-field image of the ZwCl0024+1652 region (ground-based image): ZwCl0024+1652 as seen in the Digitized Sky Survey 2 (DSS2). The image is a colour composite from DSS2 images. The field of view is 3.0 degrees. The cluster of galaxies is in the centre of the image.

Name: ZwCl0024+1652
Type: Early Universe : Galaxy : Grouping : ClusterEarly Universe : Cosmology : Phenomenon : Dark Matter
Category: CosmologyGalaxies
Constellation: Pisces
Distance: z=0.39 (redshift)
Release date: 15 May 2007, 19:00
Credit: Davide De Martin (ESA/Hubble), the ESA/ESO/NASA Photoshop FITS Liberator & Digitized Sky Survey 2

Ground-based, wide-field image of the ZwCl0024+1652 region: Wide-field image of the night sky. On the right is the asterism "Great Square of Pegasus", and to the left is the constellation of Pisces, in which the cluster of galaxies ZwCl0024+1652 is located.

Name: Pegasus, Pisces
Type: Milky Way : Sky Phenomenon : Night Sky : Asterism
Category: Miscellaneous
Release date: 15 May 2007, 19:00
Credit: A. Fujii