A Horseshoe Einstein Ring from Hubble
Explanation:
What's large and blue and can wrap itself around an entire galaxy?
A
gravitational lens
mirage.
Pictured above,
the gravity of a luminous red galaxy
(
LRG) has
gravitationally distorted
the light from a much more distant blue galaxy.
More typically, such light bending results in
two discernible images of the distant galaxy,
but here the
lens alignment
is so precise that the background galaxy is distorted into a horseshoe --
a nearly complete ring.
Since such a
lensing effect
was generally predicted in some detail by
Albert Einstein over
70 years ago,
rings
like this are now known as
Einstein Rings.
Although LRG 3-757 was discovered in 2007 in data from the
Sloan Digital Sky Survey (SDSS),
the image shown above is a follow-up observation taken with the
Hubble Space Telescope's
Wide Field Camera 3.
Strong gravitational lenses like LRG 3-757 are more than oddities --
their multiple properties allow astronomers to determine the mass and
dark matter
content of the foreground galaxy lenses.
Best Short Astronomy Videos:
APOD editor to speak in New York City on Friday, January 6
Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell
(USRA)
NASA Web Site Statements, Warnings,
and Disclaimers
NASA Official: Jay Norris.
Specific
rights apply.
A service of:
LHEA at
NASA /
GSFC
& Michigan Tech. U.
