title: Interstellar carbon in meteorites.
abstract: The Murchison and Allende chondrites contain up to 5 parts per million carbon that is enriched in carbon-13 by up to + 1100 per mil (the ratio of carbon-12 to carbon-13 is approximately 42, compared to 88 to 93 for terrestrial carbon). This "heavy" carbon is associated with neon-22 and with anomalous krypton and xenon showing the signature of the s-process (neutron capture on a slow time scale). It apparently represents interstellar grains ejected from late-type stars. A second anomalous xenon component ("CCFXe") is associated with a distinctive, light carbon (depleted in carbon-13 by 38 per mil), which, however, falls within the terrestrial range and hence may be of either local or exotic origin.
authors.forename: P K
authors.initials: PK
authors.lastname: Swart
authors.forename: M M
authors.initials: MM
authors.lastname: Grady
authors.forename: C T
authors.initials: CT
authors.lastname: Pillinger
authors.forename: R S
authors.initials: RS
authors.lastname: Lewis
authors.forename: E
authors.initials: E
authors.lastname: Anders