Plutonium-244 in the Early Solar System and Isotopic Anomalies observed for Barium, Neodymium and Carbon in Carbonaceous Chondrites

1995 ◽  
Vol 68 (3) ◽  
Author(s):  
P. K. Kuroda ◽  
W. A. Myers
2020 ◽  
Vol 6 (42) ◽  
pp. eaay2724
Author(s):  
Alexander N. Krot ◽  
Kazuhide Nagashima ◽  
James R. Lyons ◽  
Jeong-Eun Lee ◽  
Martin Bizzarro

The Sun is 16O-enriched (Δ17O = −28.4 ± 3.6‰) relative to the terrestrial planets, asteroids, and chondrules (−7‰ < Δ17O < 3‰). Ca,Al-rich inclusions (CAIs), the oldest Solar System solids, approach the Sun’s Δ17O. Ultraviolet CO self-shielding resulting in formation of 16O-rich CO and 17,18O-enriched water is the currently favored mechanism invoked to explain the observed range of Δ17O. However, the location of CO self-shielding (molecular cloud or protoplanetary disk) remains unknown. Here we show that CAIs with predominantly low (26Al/27Al)0, <5 × 10−6, exhibit a large inter-CAI range of Δ17O, from −40‰ to −5‰. In contrast, CAIs with the canonical (26Al/27Al)0 of ~5 × 10−5 from unmetamorphosed carbonaceous chondrites have a limited range of Δ17O, −24 ± 2‰. Because CAIs with low (26Al/27Al)0 are thought to have predated the canonical CAIs and formed within first 10,000–20,000 years of the Solar System evolution, these observations suggest oxygen isotopic heterogeneity in the early solar system was inherited from the protosolar molecular cloud.


2010 ◽  
Vol 291 (1-4) ◽  
pp. 39-47 ◽  
Author(s):  
R.G.A. Baker ◽  
M. Schönbächler ◽  
M. Rehkämper ◽  
H.M. Williams ◽  
A.N. Halliday

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Timothy O’Brien ◽  
John A. Tarduno ◽  
Atma Anand ◽  
Aleksey V. Smirnov ◽  
Eric G. Blackman ◽  
...  

AbstractMeteorite magnetizations can provide rare insight into early Solar System evolution. Such data take on new importance with recognition of the isotopic dichotomy between non-carbonaceous and carbonaceous meteorites, representing distinct inner and outer disk reservoirs, and the likelihood that parent body asteroids were once separated by Jupiter and subsequently mixed. The arrival time of these parent bodies into the main asteroid belt, however, has heretofore been unknown. Herein, we show that weak CV (Vigarano type) and CM (Mighei type) carbonaceous chondrite remanent magnetizations indicate acquisition by the solar wind 4.2 to 4.8 million years after Ca-Al-rich inclusion (CAI) formation at heliocentric distances of ~2–4 AU. These data thus indicate that the CV and CM parent asteroids had arrived near, or within, the orbital range of the present-day asteroid belt from the outer disk isotopic reservoir within the first 5 million years of Solar System history.


1991 ◽  
Vol 143 ◽  
pp. 550-550 ◽  
Author(s):  
N. Prantzos

The implications of the nucleosynthetic activity of WR stars are reassessed, in view of recent experimental and observational data. It is confirmed that WR stars may 1) contribute significantly (up to ~20%) to the ~3 M⊙ of 26Al detected in the galactic plane through its 1.8 MeV line, 2) be responsible for the isotopic anomalies of 22Ne and 25,26Mg, detected in galactic cosmic rays (GCR), and 3) be responsible for the inferred presence of 26Al and 107Pd in the early solar system (and, perhaps, some other nuclei as well).


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