The planet, dubbed HAT-P-1, is roughly one-third larger than Jupiter but only weighs half as much, astronomers with the Harvard-Smithsonian Center for Astrophysics said.More details at Reuters.
The planet is about one-quarter the density of water, Harvard-Smithsonian fellow Gaspar Bakos in a statement.
"It's lighter than a giant ball of cork," he said.
HAT-P-1 revolves around its parent star once every 4.5 days in an orbit one-seventh of the distance from Mercury to the Sun, according to Bakos and other Smithsonian astronomers.
Its parent star, one of a double-star system, is about 450 light-years from Earth.
Scientists discover giant planet orbiting star
Posted on Sunday, Sep 17 2006 @ 09:55 CEST by Thomas De Maesschalck
Scientists reported earlier this week that they have discovered an unusually large and light planet orbiting a start that could force them to reexamine theories about how planets are formed.