Alpha Centauri Scoped for Earth-Like Planets

To get around that limitation, Guedes and her colleagues plan to use relatively small, ground-based telescopes to make more than 90,000 observations of Alpha Centauri B over five years.

With that number of observations, their hope is that any wobbling can be spotted and separated from the background noise of other stars. The technique is unusual, and only makes sense when the star and its planets are near Earth.

"What I wonder is why didn't someone think to do it before," said Guedes. "The answer is that it takes 90,000 observations."

All those observations are expected to serve another function as well. Stellar scientists hope to find a window into the star's interior by searching the noise for p-modes (p for pressure) of sound waves inside Alpha Centauri B.

"P-mode...frequency is determined by the structure of the star," said stellar researcher Sarbani Basu of Yale University. The signals could reveal such details as how much helium the star contains and the temperature of its core.

"In the case of the sun, p modes have been used very, very successfully to determine solar structure and dynamics to an amazing degree of precision," said Basu. "For stars other than the sun, we do not expect such precise results, but nevertheless, the frequencies of these modes will enable us to build up a picture of the interior of these stars and allow us to check if we had been modeling these correctly."

Related Links:

Irene Klotz's blog: Space Diary

Larry O'Hanlon's blog: Earth Impacts

Alpha Centauri in science fiction

How Stuff Works: Planet Hunting