LINK<\/strong><\/a><\/p>\n“As the earliest dated solids, calcium\u2013aluminum-rich inclusions (CAIs) provide a unique window into the early solar system. However, for many elements, CAIs have been shown to exhibit a very different nucleosynthetic isotope signature from that of later-formed bulk meteorites. To explore this critical difference between solar system materials, we investigate a broad set of CAI samples for both mass-dependent and non-mass-dependent (nucleosynthetic) isotope variations in the siderophile element nickel (Ni). We find that fine-grained CAIs show little if any mass-dependent Ni isotopic fractionation, whereas coarse-grained inclusions exhibit a broad range of isotopically heavy signatures. Because mass-dependent variations appear to be coupled with nucleosynthetic anomalies in CAIs, a part of this Ni isotope variability could be due to thermal processing that acted on these samples. Nucleosynthetic Ni isotopic signatures show that CAIs share a genetic heritage with carbonaceous meteorites and provide a clear distinction from the isotopic reservoirs occupied by terrestrial Ni and non-carbonaceous meteorites. However, whereas nucleosynthetic Ni isotope heterogeneity in previously investigated bulk meteorites was ascribed to variation in the neutron-poor isotope 58Ni, we here find that CAI signatures require variability in other, more neutron-rich Ni isotopes. Taken in aggregate with previous work, this highlights a change in the nucleosynthetic character from CAIs to later-formed solids that cannot be explained by variable admixture of a single presolar phase or material from a specific supernova shell. Instead, these data reveal the complex evolution of the solar system, including blending and reprocessing of matter from several generations and types of stars.”<\/p>\n","protected":false},"excerpt":{"rendered":"
Jan Render, Gregory A. Brennecka, Shui-Jiong Wang, Laura E. Wasylenki, and Thorsten Kleine The Astrophysical Journal, Volume 862, Number 1 Published: 19 July 2018 LINK “As the earliest dated solids, calcium\u2013aluminum-rich inclusions (CAIs) provide a…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[66,585,72,586,71],"tags":[4616,1846,898,4615,4039],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/15998"}],"collection":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=15998"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/15998\/revisions"}],"predecessor-version":[{"id":15999,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/15998\/revisions\/15999"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=15998"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=15998"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=15998"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}