|10-26-2006, 10:06 PM||#1|
Star Explosion is Suprisingly Neat & Tidy
By Jeanna Bryner
posted: 26 October 2006
05:23 pm ET
Stars donít always rip apart in violent explosions. Some blow up in an orderly fashion.
A star named Cassiopeia A blew up in such a tidy manner that it retained much of its original onion-like layering [image].
"We've found new bits of the 'onion' layers that had not been seen before," said co-researcher Lawrence Rudnick of the University of Minnesota. "This tells us that the star's explosion was not chaotic enough to stir its remains into one big pile of mush."
The work was led by Jessica Ennis, also of the University of Minnesota.
Cassiopeia A (Cas A) is a supernova remnant within our Milky Way Galaxy, located 10,000 light-years away in the constellation Cassiopeia. The original star, about 15 to 20 times more massive than our Sun, died in a cataclysmic supernova.
Like all mature, massive stars, the Cas A star was once neat and tidy, consisting of concentric shells made up of various chemical elements: The outer layers held lighter elements, such as hydrogen, the middle layers were lined with heavier elements like neon, and its core was stacked with the heaviest elements such as iron.
Until now, scientists couldnít figure out what happened to the star when it ripped apart. One idea purported the star exploded in a more or less uniform fashion, flinging its layers out in successive order. If this were the case, those layers should be preserved in the expanding debris. While previous observations revealed parts of some of these layers, others were missing.
A false-color image taken by Spitzer. The faint blue glow surrounding Cassiopeia A is material energized by the faster-moving forward shock wave. Green, yellow and red primarily represent material that was ejected in the explosion and heated by the slower reverse shock wave. Credit: NASA/JPL-Caltech/Univ. of Minn.
|Display Modes||Rate This Thread|