skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Molybdenum Isotopes in Presolar Silicon Carbide Grains: Details of s -process Nucleosynthesis in Parent Stars and Implications for r - and p -processes

Journal Article · · The Astrophysical Journal (Online)
ORCiD logo [1]; ORCiD logo [2]; ORCiD logo [3]; ORCiD logo [1]; ORCiD logo [4]; ORCiD logo [1]
  1. Univ. of Chicago, IL (United States); Chicago Center for Cosmochemistry, Chicago, IL (United States)
  2. Univ. of Chicago, IL (United States); Chicago Center for Cosmochemistry, Chicago, IL (United States); Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
  3. Max Planck Society, Mainz (Germany)
  4. Univ. of Chicago, IL (United States); Chicago Center for Cosmochemistry, Chicago, IL (United States); Argonne National Lab. (ANL), Lemont, IL (United States)
+ Show Author Affiliations

We have analyzed molybdenum isotopes, together with strontium and barium isotopes, in 18 presolar silicon carbide grains using the Chicago Instrument for Laser Ionization (CHILI), a resonance ionization mass spectrometer. All observed isotope ratios can be explained by mixtures of pure s-process matter with isotopically solar material. Grain residues were subsequently analyzed for carbon, nitrogen, silicon, and sulfur isotopes, as well as a subset for 26Al–26Mg systematics using the NanoSIMS. These analyses showed that all but one grain are mainstream grains, most probably coming from low-mass asymptotic giant branch (AGB) stars. One grain is of the AB type, for which the origin is still a matter of debate. The high precision of molybdenum isotope measurements with CHILI provides the best estimate to date for s-process molybdenum made in low-mass AGB stars. The average molybdenum isotopic abundances produced by the s-process found in the analyzed mainstream SiC grains are 0% 92Mo, 0.73% 94Mo, 13.30% 95Mo, 36.34% 96Mo, 9.78% 97Mo, 39.42% 98Mo, and 0.43% 100Mo. Solar molybdenum can be explained as a combination of 45.9% s-process, 30.6% r-process, and 23.5% p-process contributions. Moreover, the observed variability in the individual grain data provides insights into the variability of conditions (neutron density, temperature, and timescale) during s-process nucleosynthesis in the grains' parent stars, as they have subtle effects on specific molybdenum isotope ratios. Lastly, the results indicate that the ratio between p- and r-process molybdenum in presolar SiC from many different types of parent stars is Mo p /Mo r = 0.767, the value inferred for the solar system and consistent with what has been found in bulk samples and leachates of primitive meteorites.

Research Organization:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Organization:
USDOE National Nuclear Security Administration (NNSA)
Grant/Contract Number:
AC52-07NA27344
OSTI ID:
1544506
Report Number(s):
LLNL-JRNL-768104; 958808
Journal Information:
The Astrophysical Journal (Online), Vol. 877, Issue 2; ISSN 1538-4357
Publisher:
Institute of Physics (IOP)Copyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 21 works
Citation information provided by
Web of Science

References (90)

Presolar SiC in chondrites: How variable and how many sources? journal June 1993
Interstellar grains in meteorites: I. Isolation of SiC, graphite and diamond; size distributions of SiC and graphite journal January 1994
Presolar SiC Grains of Type A and B: Their Isotopic Compositions and Stellar Origins journal September 2001
The Nubase2012 evaluation of nuclear properties journal December 2012
Ba isotopic compositions in stardust SiC grains from the Murchison meteorite: Insights into the stellar origins of large SiC grains journal November 2013
Constraining the 13 C neutron source in AGB stars through isotopic analysis of trace elements in presolar SiC journal August 2007
The origin and evolution of r - and s -process elements in the Milky Way stellar disk journal January 2016
Constraints on Stellar Grain Formation from Presolar Graphite in the Murchison Meteorite journal December 1996
The s-process in low-metallicity stars - II. Interpretation of high-resolution spectroscopic observations with asymptotic giant branch models: The s-process in low-metallicity stars - II journal October 2011
GALACTIC CHEMICAL EVOLUTION AND SOLAR s -PROCESS ABUNDANCES: DEPENDENCE ON THE 13 C-POCKET STRUCTURE journal April 2014
GALACTIC CHEMICAL EVOLUTION: THE IMPACT OF THE 13 C-POCKET STRUCTURE ON THE s -PROCESS DISTRIBUTION journal January 2017
Production of Mo and Ru Isotopes in Neutrino-driven Winds: Implications for Solar Abundances and Presolar Grains journal October 2018
Molybdenum isotopic evidence for the origin of chondrules and a distinct genetic heritage of carbonaceous and non-carbonaceous meteorites journal November 2016
Hf-W chronology of CR chondrites: Implications for the timescales of chondrule formation and the distribution of 26Al in the solar nebula journal February 2018
Origin of isotopic heterogeneity in the solar nebula by thermal processing and mixing of nebular dust journal December 2012
Molybdenum isotope anomalies in meteorites: Constraints on solar nebula evolution and origin of the Earth journal December 2011
Nucleosynthesis in Asymptotic Giant Branch Stars: Relevance for Galactic Enrichment and Solar System Formation journal September 1999
Placing the Sun and Mainstream S[CLC]i[/CLC]C Particles in Galactic Chemodynamic Evolution journal July 1997
Placing the Sun in Galactic Chemical Evolution: Mainstream SiC Particles journal July 1997
Evolution, Nucleosynthesis, and Yields of Low-Mass Asymptotic Giant Branch Stars at Different Metallicities journal April 2009
Molybdenum Nucleosynthetic Dichotomy Revealed in Primitive Meteorites journal April 2002
Stardust in meteorites journal November 2011
KADoNiS- The Karlsruhe Astrophysical Database of Nucleosynthesis in Stars conference January 2006
The Karlsruhe Astrophysical Database of Nucleosynthesis in Stars Project – Status and Prospects journal June 2014
Anomalous odd- to even-mass isotope ratios in resonance ionization with broad-band lasers journal August 1989
Co-Production of Light p -, s - and r -Process Isotopes in the High-Entropy Wind of Type II Supernovae journal January 2009
The puzzle of silicon, titanium, and magnesium anomalies in meteoritic silicon carbide grains journal July 1994
INTERSTELLAR EXPOSURE AGES OF LARGE PRESOLAR SiC GRAINS FROM THE MURCHISON METEORITE journal March 2009
INTERSTELLAR RESIDENCE TIMES OF PRESOLAR SiC DUST GRAINS FROM THE MURCHISON CARBONACEOUS METEORITE journal May 2009
CONVECTIVE-REACTIVE PROTON- 12 C COMBUSTION IN SAKURAI'S OBJECT (V4334 SAGITTARII) AND IMPLICATIONS FOR THE EVOLUTION AND YIELDS FROM THE FIRST GENERATIONS OF STARS journal January 2011
Production of the Light p-Process Nuclei in Neutrino-driven Winds journal March 1996
Carbon, nitrogen, magnesium, silicon, and titanium isotopic compositions of single interstellar silicon carbide grains from the Murchison carbonaceous chondrite journal July 1994
NanoSIMS: Technical Aspects and Applications in Cosmochemistry and Biological Geochemistry journal May 2013
Sulfur Molecule Chemistry in Supernova Ejecta Recorded by Silicon Carbide Stardust journal January 2012
NanoSIMS STUDIES OF SMALL PRESOLAR SiC GRAINS: NEW INSIGHTS INTO SUPERNOVA NUCLEOSYNTHESIS, CHEMISTRY, AND DUST FORMATION journal July 2010
New Insights into the Galactic Chemical Evolution of Magnesium and Silicon Isotopes from Studies of Silicate Stardust journal December 2018
Sulfur in presolar silicon carbide grains from asymptotic giant branch stars journal May 2015
Small SiC grains and a nitride grain of circumstellar origin from the Murchison meteorite: Implications for stellar evolution and nucleosynthesis journal March 1996
Isotopic systematics of presolar silicon carbide from the Orgueil (CI) chondrite: Implications for solar system formation and stellar nucleosynthesis journal December 1997
Age of Jupiter inferred from the distinct genetics and formation times of meteorites journal June 2017
Resonance ionization mass spectrometry for precise measurements of isotope ratios journal November 2009
Host Phase of a Strange Xenon Component in Allende journal December 1975
Interstellar diamonds in meteorites journal March 1987
THE 13 C-POCKET STRUCTURE IN AGB MODELS: CONSTRAINTS FROM ZIRCONIUM ISOTOPE ABUNDANCES IN SINGLE MAINSTREAM SiC GRAINS journal June 2014
New Constraints on the Major Neutron Source in Low-mass AGB Stars journal September 2018
STELLAR ORIGINS OF EXTREMELY 13 C- AND 15 N-ENRICHED PRESOLAR SIC GRAINS: NOVAE OR SUPERNOVAE? journal March 2016
Stellar Origin of 15 N-rich Presolar SiC Grains of Type AB: Supernovae with Explosive Hydrogen Burning journal June 2017
BARIUM ISOTOPIC COMPOSITION OF MAINSTREAM SILICON CARBIDES FROM MURCHISON: CONSTRAINTS FOR s -PROCESS NUCLEOSYNTHESIS IN ASYMPTOTIC GIANT BRANCH STARS journal April 2014
Correlated Strontium and Barium Isotopic Compositions of Acid-Cleaned Single Mainstream Silicon Carbides from Murchison journal April 2015
J-type Carbon Stars: A Dominant Source of 14 N-rich Presolar SiC Grains of Type AB journal July 2017
Common Occurrence of Explosive Hydrogen Burning in Type II Supernovae journal March 2018
Isotopic Compositions of Strontium, Zirconium, Molybdenum, and Barium in Single Presolar SiC Grains and Asymptotic Giant Branch Stars journal August 2003
THE IMPACT OF UPDATED Zr NEUTRON-CAPTURE CROSS SECTIONS AND NEW ASYMPTOTIC GIANT BRANCH MODELS ON OUR UNDERSTANDING OF THE S PROCESS AND THE ORIGIN OF STARDUST journal December 2013
The New “York” Regression: Application of an Improved Statistical Method to Geochemistry journal April 1996
Iron and Nickel Isotopic Ratios in Presolar SiC Grains journal December 2008
NanoSIMS studies of Ba isotopic compositions in single presolar silicon carbide grains from AGB stars and supernovae journal August 2007
A 15N-Poor Isotopic Composition for the Solar System As Shown by Genesis Solar Wind Samples journal June 2011
Isotopic compositions of the elements 2013 (IUPAC Technical Report) journal March 2016
Molybdenum and Zirconium Isotopes from a Supernova Neutron Burst journal September 2000
s-Process Zirconium in Presolar Silicon Carbide Grains journal August 1997
Molybdenum Isotopic Composition of Individual Presolar Silicon Carbide Grains from the Murchison Meteorite journal March 1998
Strontium Isotopic Composition in Individual Circumstellar Silicon Carbide Grains: A Record of s -Process Nucleosynthesis journal October 1998
Automated isotopic measurements of micron-sized dust: application to meteoritic presolar silicon carbide journal December 2003
Astrophysics with Extraterrestrial Materials journal September 2016
Are Presolar Silicon Carbide Grains from Novae Actually from Supernovae? journal August 2005
Discovery of s-process barium in the Murchison meteorite journal April 1990
s ‐Process Sr Isotopic Compositions in Presolar SiC from the Murchison Meteorite journal April 2004
S-process BA isotopic compositions in presolar SiC from the Murchison meteorite journal June 1993
Rare gases in the chondrite Renazzo journal August 1964
Barium isotopes in individual presolar silicon carbide grains from the Murchison meteorite journal September 2003
Analyzing individual presolar grains with CHARISMA journal September 2003
CHILI – the Chicago Instrument for Laser Ionization – a new tool for isotope measurements in cosmochemistry journal August 2016
Strontium and barium isotopes in presolar silicon carbide grains measured with CHILI—two types of X grains journal January 2018
Correction of dead time effects in time‐of‐flight mass spectrometry
  • Stephan, T.; Zehnpfenning, J.; Benninghoven, A.
  • Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, Vol. 12, Issue 2 https://doi.org/10.1116/1.579255
journal March 1994
s process in low-mass asymptotic giant branch stars journal October 2006
Beta-decay rates of highly ionized heavy atoms in stellar interiors journal May 1987
The stellar neutron capture cross sections of Zr-94 and Zr-96 journal January 1990
SULFUR ISOTOPIC COMPOSITIONS OF SUBMICROMETER SiC GRAINS FROM THE MURCHISON METEORITE journal January 2015
Least squares fitting of a straight line with correlated errors journal January 1968
S-process Ba, Nd, and SM in presolar SiC from the Murchison meteorite journal November 1991
Stardust in meteorites [スターダストに魅せられて] journal January 2004
Co-production of light p-, s- and r-process isotopes in the high-entropy wind of type II supernovae text January 2009
Convective-reactive proton-C12 combustion in Sakurai's object (V4334 Sagittarii) and implications for the evolution and yields from the first generations of stars text January 2010
Galactic Chemical Evolution and solar s-process abundances: dependence on the 13C-pocket structure text January 2014
The 13C-Pocket Structure in AGB Models: Constraints from Zirconium Isotope Abundances in Single Mainstream SiC Grains text January 2014
Correlated Strontium and Barium Isotopic Compositions of Acid-Cleaned Single Silicon Carbides from Murchison text January 2015
Galactic Chemical Evolution: the Impact of the 13C-pocket Structure on the s-process Distribution text January 2017
Stellar origin of 15N-rich presolar SiC grains of type AB: supernovae with explosive hydrogen burning text January 2017
Production of Mo and Ru isotopes in neutrino-driven winds: implications for solar abundances and presolar grains text January 2018
s Process in low-mass Asymptotic Giant Branch Stars text January 2005

Cited By (4)

Presolar Silicon Carbide Grains of Types Y and Z: Their Molybdenum Isotopic Compositions and Stellar Origins journal August 2019
Isotopes of Barium as a Chronometer for Supernova Dust Formation journal November 2019
Isotopic Signatures of Supernova Nucleosynthesis in Presolar Silicon Carbide Grains of Type AB with Supersolar 14 N/ 15 N Ratios journal December 2019
Presolar Silicon Carbide Grains of Types Y and Z: Their Molybdenum Isotopic Compositions and Stellar Origins text January 2019

Similar Records

Molybdenum isotopic composition of individual presolar silicon carbide grains from the Murchison meteorite.
Journal Article · Sun Mar 01 00:00:00 EST 1998 · Geochim. Cosmochim. Acta · OSTI ID:1544506
+3 more
Barium isotopes in individual presolar silicon carbide grains from the Murchison meteorite.
Journal Article · Mon Sep 01 00:00:00 EDT 2003 · Geochim. Cosmochim. Acta · OSTI ID:1544506
+6 more
Simultaneous iron and nickel isotopic analyses of presolar silicon carbide grains
Journal Article · Mon Jan 01 00:00:00 EST 2018 · Geochimica et Cosmochimica Acta · OSTI ID:1544506
+8 more

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
circumstellar matter
dust
extinction
meteorites
meteors
meteoroid
nuclear reactions
nucleosynthesis
abundances
stars: AGB and post-AGB