Results 21 to 30 of about 92 (70)
Th/Nd cosmochronology and a constant r/s ratio [PDF]
Monthly Notices of the Royal Astronomical Society, 1989 Une serie de calculs numeriques est effectuee afin d'etudier la possibilite d'un effet de la metallicite sur l'exposition de neutrons pouvant expliquer la constance observee du rapport r/s (processus r/processus s) dans les etoiles avec [Fe/H]>−2.0. On trouve qu'un mecanisme base uniquement sur la dependance en metallicite de l'exposition de neutrons ...
Robert A. Malaney, William A. Fowler
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r-Process abundance universality and actinide cosmochronology
New Astronomy, 2003 We review recent observational and theoretical results concerning the presence of actinide nuclei on the surfaces of old halo stars and their use as an age determinant. We present model calculations which show that the observed universality of abundances for 56 < Z < 75 elements in these stars does not imply a unique astrophysical site for the r ...
Otsuki, Kaori +2 more
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The Nuclear Astrophysics Program at the CERN n_TOF Facility: Results and Perspectives
UniverseThe CERN n_TOF facility is a research infrastructure specifically designed for studying neutron-induced nuclear reactions. Pulsed white neutron beams are delivered toward three experimental areas, two of them at different baselines to apply the time-of ...
P. M. Milazzo +2 more
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Thresholds on star formation and the chemical evolution of galactic discs: cosmochronology and the age of the Galaxy [PDF]
Monthly Notices of the Royal Astronomical Society, 1996 Latex version 3.1, 12 pages + 15 figures, MNRAS in press, replaces earlier version in which the postscript figures had become ...
Chamcham, K., Hendry, M. A.
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The Presolar Heritage of 50Ti and 26Al Heterogeneity in the Protoplanetary Disk
The Astrophysical JournalNucleosynthetic isotope anomalies have been documented within the solar protoplanetary disk for several isotopes, including ^48 Ca, ^50 Ti, ^54 Cr, ^94 Mo, and ^96 Zr.
Kirsten K. Larsen +5 more
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The Astrophysical Journal, 1979 Recent data on isotopic anomalies of various elements in meteorites are interpreted in the picture of the birth of the Sun in a stellar OB association. The following points are suggested by this analysis. (a) The standard picture of stellar nucleosynthesis by an exponentially decreasing stellar activity throughout the galactic life remains tenable. (b)
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Radioactive nuclei from cosmochronology to habitability
Progress in Particle and Nuclear Physics, 2018 Review published in Progress in Particle and Nuclear Physics. The article is being published Open Access, access to the full article is not restricted in any way.
Lugaro, Maria +2 more
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Potential Chronological Disturbance of the D’Orbigny Angrite Inferred from Discordant 26Al Ages
The Astrophysical Journal LettersAngrites originate from the early-formed differentiated angrite parent body. The pristine volcanic angrite D’Orbigny is devoid of brecciation, shock effects, or any evidence of secondary processes and is thus key for studying the early stages of ...
Cécile Deligny +4 more
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White dwarf cosmochronology: Techniques and uncertainties [PDF]
Proceedings of the International Astronomical Union, 2008 AbstractWhite dwarfs represent the endpoint of the evolution of the large majority of stars formed in the Galaxy. In the last two decades observations and theory have improved to a level that makes possible to employ white dwarfs for determining ages of the stellar populations in the solar neighborhood, and in the nearest star clusters.
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NWA 11562: A Unique Ureilite with Extreme Mg-rich Constituents
The Planetary Science JournalA comprehensive study of an ungrouped achondrite meteorite, North West Africa (NWA) 11562, was conducted, involving petrology, mineralogy, and mass-independent chromium isotopic composition. NWA 11562 comprises 34.9 vol% olivine, 56.1 vol% pyroxenes, 6.7
Mingbao Li +6 more
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