The Hubble Space Telescope
has cast its eye on a fuzzy patch of emissions in space known as the Cat's Eye
Nebula, revealing a series of concentric rings in new detail.
Formally cataloged NGC 6543,
the Cat's Eye is a planetary nebula, a class of objects so-named because when
they were first noticed, through the small telescopes available to early astronomers,
they looked like the fuzzy disks of Jupiter and the other gas-giant planets.
Like others, the Cat's Eye
formed when a Sun-like star gently ejected its outer gaseous layers toward the
end of its life. The concentric rings are actually shells or bubbles of expelled
gas and dust, only their edges being evident. The new view, released today,
reveals at least 11 of these bubbles, seen like layers of an onion when sliced
in half.
To create the rings, the
dying star ejected material in intervals of about 1,500 years, astronomers said.
Scientists have only recently
learned that the formation of these rings is likely to be the rule rather than
the exception with planetary nebulas. That is a surprise, because researchers
didn't expect dying stars to expel mass at regular intervals.
The cycles could be related
to recurring magnetic activity, astronomers say. An orbiting companion star
might also be the cause. Or, perhaps the material is ejected constantly and
the bubbles form later, like waves.
-- SPACE.com
Staff
Credit: NASA, ESA, HEIC,
and The Hubble Heritage Team (STScI/AURA) Acknowledgment: R. Corradi (Isaac
Newton Group of Telescopes, Spain) and Z. Tsvetanov (NASA)
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