Hubble Eyes Signs of Nearby Planets

摘要

About the last thing Brad A. Smith expected to find when he examined the region around a young, nearby star was a large-scale replica of one of the rings of Saturn. Like the planet's icy rings, the band of dust around the star HR 4796A, some 220 light-years from Earth, is narrow and has sharp edges. And, just as Saturn's rings are corralled by the gravity of closely orbiting moons, Smith and his colleagues suggest that the stellar dust ring owes its slender shape to the guiding influence of one or more massive bodies, most likely fledgling planets.