%0 Journal Article
%T Nitrogen isotopes in AGB carbon stars and presolar SiC grains: a challenge for stellar nucleosynthesis
%+ Laboratoire Univers et Particules de Montpellier (LUPM)
%A Hedrosa, R.
%A Abia, C.
%A Busso, M.
%A Cristallo, S.
%A Domínguez, I.
%A Palmerini, S.
%A Plez, Bertrand
%A Straniero, O.
%Z 2 figures, 21 pages, Accepted in Astrophysical Journal Letters
%< avec comité de lecture
%Z LUPM:13-006
%@ 2041-8205
%J The Astrophysical journal letters
%I Bristol : IOP Publishing
%V 768
%P L11
%8 2013-04-18
%D 2013
%Z 1303.6418
%Z 2013arXiv1303.6418H
%R 10.1088/2041-8205/768/1/L11
%Z Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR]
%Z Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR]Journal articles
%X Isotopic ratios of C, N, Si, and trace heavy elements in presolar SiC grains from meteorites provide crucial constraints to nucleosynthesis. A long-debated issue is the origin of the so-called A+B grains, as for them no stellar progenitor has so far been clearly identified on observational grounds. We report the first spectroscopic measurements of 14N/15N ratios in Galactic carbon stars of different spectral types and show that J- and some SC-type stars might produce A+B grains, even for 15N enrichments previously attributed to novae. We also show that most mainstream (MS) grains are compatible with the composition of N-type stars, but might also descend, in some cases, from SC stars. From the theoretical point of view, no astrophysical scenario can explain the C and N isotopic ratios of SC, J and N-type carbon stars together, as well as those of many grains produced by them. This poses urgent questions to stellar physics.
%G English
%L hal-00815256
%U https://hal.science/hal-00815256
%~ IN2P3
%~ CNRS
%~ UNIV-MONTP2
%~ LUPM
%~ MIPS
%~ UNIV-MONTPELLIER
%~ LUPM_AS
%~ UM1-UM2