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Cat's Eye Nebula

June 24, 2010

It's often the case that an artist's work isn't fully appreciated until after the artist dies. And the same thing is true in the stars. We appreciate a star's beauty as it twinkles through the night sky, but its greatest glory -- a masterpiece of color and form -- is also its final creation.

An example is the Cat's Eye Nebula, in the faint constellation Draco, the dragon.

Photographs show swirls and loops of green and red -- more reminiscent of a flower than a cat's eye. But the nebula's real beauty is not as a photograph, but as a sculpture. It consists of an elongated bubble of hot gas attached to two bigger bubbles. Jets of gas shoot into space from the tops of the bubbles.

The process that sculpted the Cat's Eye is the death of its central star, which originally was several times as massive as the Sun.

Thousands of years ago, it began throwing big rings of gas and dust off of its surface. And about a thousand years ago, it began ejecting its outer layers of gas into space -- a process that eventually will leave nothing but its hot, dense core. Ultraviolet energy from the core lights up the expanding bubbles of gas, making them glow brightly. And the nebula's shape may be sculpted by the gravity of a small companion star.

The Cat's Eye Nebula is expanding at tens of thousands of miles per hour. Eventually, it'll spread so thinly that it will fade from sight -- and a work of cosmic art will die with its artist.

Script by Damond Benningfield, Copyright 2010

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