Astronomers have known since 1991 that a ring of dust, a likely vestige of planet formation, surrounds the nearby star HR 4796A. Researchers now report the first evidence that the ring contains complex organic molecules.
Alycia Weinberger of the Carnegie Institution of Washington (D.C.) and her colleagues observed the ring with a near-infrared camera on the Hubble Space Telescope. Comparing those images with Hubble images made in visible light, the team showed that the dust scattered much more infrared light than visible light. And that's the same pattern displayed by a group of organic compounds called tholins.
Astronomers have found tholins in comets and the atmosphere of Saturn's moon Titan, but the new study provides the first strong evidence for the material outside the solar system, Weinberger's team says in the Feb. 1 Astrophysical Journal Letters.