Abell 1689 is one of the most massive clusters of galaxies known. It is located some 2.2 billion light years away in the constellation of Virgo. From this distance the individual galaxies are mere fuzzy specks of light, and the whole cluster is similar in appearance to a faint loose globular.
In this image there are more than 150 faint yellowish galaxies scattered throughout the field, concentrated towards the center of the image. The clump of relatively bright galaxies in the center are mostly supermassive ellipticals, with large populations of older yellow stars. The image is somewhat noisy as these galaxies are at the limit of what the ToUCam can pick up - all being 17th to 19th magnitude - with the faintest I have been able to confirm, having a magnitude of 19.3
Abell 1689 is also a gravitational lens, deflecting rays of light that pass through it, in line with Einstein's general theory of relativity. This gravitational lensing effect magnifies, distorts, and brighten the light of distant galaxies that by chance happen to lie behind the cluster.
In very deep images from the Hubble Space Teleccope, these background galaxies are visible as tangential arcs of light around the center of the cluster.
By magnifying the images of distant background galaxies, gravitational lenses such as Abell 1689 allow detailed views of very distant galaxies to be obtained. Some of the background galaxies are up to 13 billion light years distant and are the furthest and thus youngest galaxies ever observed.
OPTICS 10" Newtonian f/5.2
MOUNT Losmandy G11 equatorial
CAMERA Philips ToUCam Pro SC1 webcam
EXPOSURE 76 x 120s
DATE/TIME 30/05/2006 09:08 UTC
LOCATION My backyard observatory in west Auckland, New Zealand