Sonic Booms
[SFX: Middle C; note and ring out]
When a massive star goes "boom," the explosion might be driven in part by sound -- powerful waves of energy from the star's core.
The exploding stars are known as supernovae. They occur when the core of a massive star can no longer produce energy, so it collapses to form a neutron star. The layers of gas around the core fall inward, then rebound, creating a shockwave that eventually will blast the star to bits.
But simulations show that the shockwave forms, then stalls, in just a fraction of a second. It needs an extra "kick" to reinvigorate it enough to plow through the star's outer layers, which can be millions of miles thick.
Several mechanisms might be involved, including strong magnetic fields. And several groups of astronomers are looking at the role of sound waves.
A team led by Arizona astronomer Adam Burrows found that the core "wiggles" back and forth. In simulations, the vibration creates powerful sound waves. The waves are at frequencies that are similar to the notes on a musical scale, within a few notes of middle C. [SFX: Middle C, and notes above and below.] As they move out, they give extra energy to the shock wave.
Texas astronomers are looking at the role of sound, too. They've found that the spinning core can flatten out, and even form a cigar shape. That, too, would create sound waves powerful enough to help blast the star to cosmic dust.
Script by Damond Benningfield, Copyright 2006
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