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This image of Uranus, its ring system,
and two of its satellites Miranda (top-center) and Ariel
(bottom-left) is from Subaru Telescope's Coronagraphic Imager
with Adaptive Optics (CIAO) combined with Subaru Telescope's
adaptive optics system (AO).
On March 13, 1781, British astronomer William Herschel discovered
an object that appeared large compared to a star during
observations with a homemade 6.3 inch (16 cm) telescope.
The object, which was initially thought to be a comet, turned
out to be a new planet outside Saturn's orbit, and was named
Uranus.
Uranus revolves around the Sun in approximately 84 years
on an elliptic orbit whose average radius is approximately
1.7 billion miles (2.8 billion kilometers). Unlike other
planets, Uranus spins on its side with respect to its orbital
plane. Since 1851, over 10 satellites and 10 rings have
been discovered around Uranus.
This image was taken during tests of the combined use of
CIAO and AO in July 2001. It combines near-infrared images
in three different filters, so the colors are not the same
as what we would see in the optical. In this color scheme,
methane, the dominant component of Uranus's atmosphere,
shows up as blue.
Scientists from several research institutes and universities,
in addition to the National Astronomical Observatory of
Japan, participated in the development of CIAO and Subaru
Telescope's AO system. The team from Kobe University processed
this image.
The image was first introduced to the public in a Japanese
television program "Youkoso Senpai" ("Welcome
back Graduate!") by the Japan Broadcasting Corporation
(NHK) on January 20, 2002.
February 21, 2002 |