Presolar Grains from Novae

By S. Amari, Xia Gao, L. Nittler, E. Zinner, J. José, M. Hernanz, R. Lewis. 2000

182 citations recorded by the source corpus.

We report the discovery of five SiC grains and one graphite grain isolated from the Murchison carbonaceous meteorite whose major-element isotopic compositions indicate an origin in nova explosions. The grains are characterized by low 12C/13C (4-9) and 14N/15N (5-20) ratios, large excesses in 30Si (30Si/28Si ratios range to 2.1 times solar), and high 26Al/27Al ratios. These isotopic signatures are theoretically predicted for the ejecta from ONe novae and cannot be matched by any other stellar sources. Previous studies of presolar grains from primitive meteorites have shown that the vast majority formed in red giant outflows and supernova ejecta. Although a classical nova origin was suggested for a few presolar graphite grains on the basis of 22Ne enrichments, this identification is somewhat ambiguous since it is based on only one trace element. Our present study presents the first evidence for nova grains on the basis of major element isotopic compositions of single grains. We also present the results of nucleosynthetic calculations of classical nova models and compare the predicted isotopic ratios with those of the grains. The comparison points toward massive ONe novae if the ejecta are mixed with material of close-to-solar composition.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/bb3df956fd3f1207ed3e37696ab8dcdb8672db8d

How researchers see this paper

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In Astronomy and Astrophysics

1. L. Nittler
2. F. Ciesla
3. E. Zinner
4. D. Clayton
5. S. Amari
6. J. José
7. M. Hernanz
8. S. Starrfield

In Instrumentation

1. M. Busso
2. F. Ciesla
3. L. Nittler
4. G. Wasserburg
5. K. Lodders
6. Jon Fortney
7. M. Marley
8. N. Madhusudhan

Citations in the corpus

• Astrophysics with Presolar Stardust (2004, background): “Fewer then ten grains of SiC and graphite have been reported with isotopic signatures strongly pointing to a nova origin (Amari et al. 2001a, Nittler & Alexander 2003a).”
• The Imprint of Nova Nucleosynthesis in Presolar Grains (2002, background): “In fact, a comparison between grain data and nova models suggests that these grains formed in ONe novae with a white dwarf mass of at least 1.25M⊙ (Amari et al. 2001).”
• The Effects of Thermonuclear Reaction-Rate Variations on Nova Nucleosynthesis: A Sensitivity Study (2002, background): “Sixth, the recent discovery of several presolar SiC grains with anomalous C, N, Al, and Si isotopic ratios points toward a nova origin (Amari et al. 2001).”
• Astrophysics with Extraterrestrial Materials (2016, background): “%) of presolar SiC, graphite, silicate, and oxide grains (Amari et al. 2001a, Gyngard et al. 2010b, Leitner et al. 2012), in addition to a few of the 13C-rich grains just discussed (Heck et al. 2007).”
• Presolar SiC Grains of Type A and B: Their Isotopic Compositions and Stellar Origins (2001, background): “Vol. 559 have been identiÐed as originating from novae (Amari et al. 2001a).”
• Cool Bottom Processes on the Thermally Pulsing Asymptotic Giant Branch and the Isotopic Composition of Circumstellar Dust Grains (2002, background): “They belong to the very small class (6 known) of carbon-rich grains attributed to novae on the basis of C, N, and Si isotopic compositions, and they are not A and B grains (Amari et al. 2001c).”