Sunday, January 01, 2006

Alpha Centauri B is Ringing Like a Bell

At nearly 4.5 light years distance from the earth, the stars that make up the 'Pointers' near the Constellation of the Southern Cross are close enough to make any astronomer salivate with anticipation of seeing a Sun-like star outside our Solar System, but far enough away to require a minimum 40 years of one-way travel even at our fastest theoretical speed (using Solar Sails.)

So instead of planning a mission, scientists rely on astronomers to paint a picture of what the stars look like and what they are doing.

Alpha Centauri B is a little cooler and a little smaller than our Sun, but no less interesting. Using two telescopes simultaneously, astronomers have been able to measure the pulsing nature of the star, even providing approximate measurements of how much its interior activity is altering it's size.
Much like the vibrations of a bell, these alterations in surface area caused by churning gases, send rippling sound waves bouncing around the interior of the star and reverberating out into space.

No, you can't hear it at all even if you try real hard. But by measuring the Doppler Effect on wavelengths of light emitted from the star, astronomers can make their estimations about size and changes and whatnot...

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