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Credit & Copyright: W. N. Colley
(U. Virgina
& E. Turner
(Princeton), J.A. Tyson
(UC Davis),
HST,
NASA
Explanation:
What are those strange blue objects?
Many are images of a single,
unusual, beaded, blue, ring-like
galaxy which just happens to line-up behind a giant
cluster of galaxies.
Cluster galaxies here appear yellow and --
together with the cluster's dark matter --
act as a gravitational lens.
A gravitational lens can create
several images of
background galaxies,
analogous to the many points of light
one would see while looking through a wine glass at a distant street light.
The
distinctive shape of this background galaxy --
which is probably just forming --
has allowed astronomers to deduce that it has separate
images at 4, 8, 9 and 10
o'clock,
from the center of the cluster.
Possibly even the blue smudge just left of center is yet another image!
This
spectacular photo from the
Hubble Space Telescope
was taken in October 1994.
Tomorrow's picture: telling tapistry
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NASA Official: Jay Norris. Specific rights apply.
A service of: LHEA at NASA / GSFC
& Michigan Tech. U.
Based on Astronomy Picture
Of the Day
Publications with keywords: cluster of galaxies
Publications with words: cluster of galaxies
See also: