Nuclei in the Cosmos - IX

Session

6 Evidence of nucleosynthesis in stars and presolar grains

27 Jun 2006, 11:30

CERN, Geneva

Conveners

6 Evidence of nucleosynthesis in stars and presolar grains

• Roberto Gallino (Universita' di Torino/INFN Torino)

187. Heavy elements in presolar grains: constraints on conditions in asymptotic giant branch stars

Andrew Davis (University of Chicago)

27/06/2006, 11:30

Evidences of nucleosynthesis in stars and in presolar grains

Invited

Presolar SiC grains come from a variety of kinds of stars, but the most common type, the mainstream grains, are believed to have formed in the outflows of low mass, carbon-rich asymptotic giant branch (AGB) stars. Measurements of the isotopic composition of the s-process elements Sr, Zr, Mo, Ru and Ba in individual mainstream SiC grains allow constraints of the range of conditions used...

168. On the stellar sources of presolar graphite in primitive meteorites

Ernst Zinner (Washington University)

27/06/2006, 12:00

Evidences of nucleosynthesis in stars and in presolar grains

Oral contribution

Primitive meteorites contain graphite spherules whose anomalous isotopic compositions indicate a stellar origin [1]. Because the isolation of presolar graphite grains is difficult, they have been less well studied than presolar SiC and presolar oxide grains. It has been known that the isotopic compositions of presolar graphite grains depends on their density, but detailed isotopic...

62. Isotopic Composition of Presolar Spinel Grain OC2: Constraining Intermediate-Mass Asymptotic Giant Branch Models

Maria Lugaro (University of Utrecht)

27/06/2006, 12:20

Evidences of nucleosynthesis in stars and in presolar grains

Oral contribution

Presolar spinel (MgAl2O4) grains have been recently discovered in meteorites and represent the most abundant type of presolar oxides. The O, Mg and Al isotopic compositions of the vast majority of presolar oxide grains indicate that these grains originated in red giant and asymptotic giant branch (AGB) stars of masses lower than approximately 3 solar masses. Grain OC2 has a unique...

12. Ne22 a primary source of neutron for the s-process and a major neutron poison in CEMP AGB stars

Roberto Gallino (University of Torino)

27/06/2006, 12:40

Evidences of nucleosynthesis in stars and in presolar grains

Poster contribution

In AGB stars of low mass and very low metallicity, [Fe/H]<-2, a large abundance of C12 is mixed with the envelope by each third dredge up episode. The further activation of the H burning shell at the bottom of the envelope converts almost all CNO nuclei into N14. Thus the H-burning ashes contain N14 from the original CNO nuclei, plus an increasing amount of primary N14. During the...

259. Accelerator Mass Spectrometry and Nuclear Astrophysics

Gunther Korschinek (Fachbereich Physik, Technische Universität München)

27/06/2006, 13:00

Experiments in nuclear astrophysics

Invited

Accelerator Mass Spectrometry (AMS) is an extremely sensitive method for determination of rare ions. Besides ongoing applications in quite different scientific fields it is still a rather new tool in nuclear astrophysics. In this presentation I will show the reasons for this unique sensitivity and where are the limits: from the table top machine too a large facility. Applications in...