Astronomy in the News
Mercury Spring 2008 Table of Contents
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An artist's concept of a terrestrial planet orbiting the
star Alpha Centauri B. |
Does Alpha Centauri Have Planets?
University of California, Santa Cruz
A rocky planet similar to Earth may be orbiting one of our nearest stellar neighbors and could be detected using existing techniques, according to a new study led by astronomers at the University of California, Santa Cruz.
The closest stars to our Sun are in the three-star system called Alpha Centauri, a popular destination for interstellar travel in works of science fiction. UCSC graduate student Javiera Guedes used computer simulations of planet formation to show that terrestrial planets are likely to have formed around the star Alpha Centauri B and to be orbiting in the “habitable zone” where liquid water can exist on the planet’s surface. The researchers then showed that such planets could be observed.
To
study planet formation around Alpha Centauri B, the team ran repeated
computer simulations, evolving the system for the equivalent of
200 million years each time. Because of variations in the initial
conditions, each simulation led to the formation of a different
planetary system. In every case, however, a system of multiple planets
evolved with at least one planet about the size of Earth. In many
cases, the simulated planets had orbits lying within the habitable
zone of the star.
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