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July 10, 1995
Abell 2218: A Galaxy Cluster Lens
Picture Credit: NASA, HST, WFPC2, W. Couch (UNSW)
Sometimes one of the largest concentrations of mass known can act like a lens.
Almost all of the bright objects in this image are galaxies in the cluster
known as Abell 2218. The cluster is so massive and so compact that it bends
light from galaxies that lie behind it, causing many of them to appear as
stretched out arcs. Many dim, elongated arcs are visible on this photograph.
This picture was taken with the Wide Field Planetary Camera 2 on board the
Hubble Space Telescope.
For more information about this picture see
the Space Telescope Scientific Institute's
Microlensing of the Einstein Cross
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