Small exoplanet discovered
Detection offers hope for finding other Earthlike bodies
By Ron Cowen
Astronomers have discovered the smallest planet known beyond the solar system that orbits an ordinary parent body. Weighing in at only three times the mass of Earth, the planet orbits its parent body at a distance similar to that of Venus’ distance from the sun. But because the planet orbits a body that is most likely a faint, cold brown dwarf, the planet is probably colder than that of Pluto and could not support life, reports David Bennett of the University of Notre Dame in Indiana.
Nonetheless, the detection is a milestone that gives astronomers additional hope of one day finding an alien Earth similar to home, comments David Charbonneau of the Harvard-SmithsonianCenter for Astrophysics in Cambridge, Mass.
Bennett and his colleagues found the planet because it and its parent brown dwarf acted as a set of gravitational magnifying glasses, separately bending and brightening the light of a background star that happened to lie directly behind the pair as seen from Earth. The two distinct brightenings revealed the presence of the parent body and its planet.