2026-04-18T02:21:23Zhttps://recercat.cat/oai/requestoai:recercat.cat:2117/1005332026-02-11T07:10:41Zcom_2072_1033col_2072_452950
Coordinated analysis of two graphite grains from the CO3.0 LAP 031117 meteorite: First identification of a CO Nova graphite and a presolar iron sulfide subgrain
Haenecour, P.
Floss, C.
José Pont, Jordi
Amari, S.
Lodders, K.
Jadhav, M.
Wang, A.
Gyngard, F.
Universitat Politècnica de Catalunya. Departament de Física
Universitat Politècnica de Catalunya. GAA - Grup d'Astronomia i Astrofísica
Àrees temàtiques de la UPC::Física::Astronomia i astrofísica
Meteorites
Cosmochemistry
Nucleosynthesis
Supernovae
Stars
meteorites
meteors
meteoroids
stars: astrochemistry
circumstellar matter
novae
cataclysmic variables
supernovae: general
nuclear reactions
nucleosynthesis
abundances
stars: winds
outflows
stars: formation
stars: fundamental parameters
stars: evolution.
Estels
Astroquímica
Cosmoquímica
Presolar grains constitute remnants of stars that existed before the formation of the solar system.
In addition to providing direct information on the materials from which the solar system formed, these grains provide ground-truth information for models of stellar evolution and nucleosynthesis.
Here we report the in-situ identification of two unique presolar graphite grains from the primitive meteorite LaPaz Icefield 031117. Based on these two graphite grains, we estimate a bulk presolar graphite abundance of 5-3+7 ppm in this meteorite. One of the grains (LAP-141) is characterized by an enrichment in 12C and depletions in 33,34S, and contains a small iron sulfide subgrain, representing the first unambiguous identification of presolar iron sulfide. The other grain (LAP-149) is extremely 13C-rich and 15N-poor, with one of the lowest 12C/13C ratios observed among presolar grains. Comparison of its isotopic compositions with new stellar
nucleosynthesis and dust condensation models indicates an origin in the ejecta of a low-mass CO nova. Grain LAP-149 is the first putative nova grain that quantitatively best matches nova model
predictions, providing the first strong evidence for graphite condensation in nova ejecta. Our discovery confirms that CO nova graphite and presolar iron sulfide contributed to the original building blocks of the solar system.
Peer Reviewed
Postprint (author's final draft)
2016-07
Article
Haenecour, P., Floss, C., Jose, J., Amari, S., Lodders, K., Jadhav, M., Wang, A., Gyngard, F. Coordinated analysis of two graphite grains from the CO3.0 LAP 031117 meteorite: First identification of a CO Nova graphite and a presolar iron sulfide subgrain. "Astrophysical journal", Juliol 2016, vol. 825, p. 8-1-8-9.
0004-637X
https://hdl.handle.net/2117/100533
10.3847/0004-637X/825/2/88
eng
http://creativecommons.org/licenses/by-nc-nd/3.0/es/
Open Access
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