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Star Shade Could Reveal Earthlike Exoplanets

Monday, July 17, 2006

Star shade
Image: © AMY LO
200x172

Stars shine so brightly that any planets orbiting them are lost in the glow. In fact, astronomers can only detect exoplanets indirectly by their effects on parent stars: either gravitational or, as the planet passes in front, by dimming. But a 50-meter-wide, daisy-shaped star shade could block stellar light, allowing direct observation of their planets, according to a new paper in today's Nature.

Webster Cash of the University of Colorado designed the star shade to be used in conjunction with orbiting telescopes. The thin plastic shade would cancel out a specific star's light and the telescope--trailing 15,000 miles behind--could then take in light from its distant planets. "Think of an outfielder holding up one hand to block out the sunlight as he tracks a fly ball," Cash explains. "We would use the star shade as a giant hand to suppress the light emanating from a central star by a factor of about 10 billion."

Read More: Scientific American.com -Star Shade Could Reveal Earthllike Exoplanets