{"id":26613,"date":"2021-03-01T13:26:38","date_gmt":"2021-03-01T12:26:38","guid":{"rendered":"https:\/\/karmaka.de\/?p=26613"},"modified":"2021-03-01T13:32:30","modified_gmt":"2021-03-01T12:32:30","slug":"molybdenum-isotope-dichotomy-in-meteorites-caused-by-s-process-variability","status":"publish","type":"post","link":"https:\/\/karmaka.de\/?p=26613","title":{"rendered":"Molybdenum Isotope Dichotomy in Meteorites Caused by s-Process Variability"},"content":{"rendered":"\n<p>Thomas Stephan and Andrew M. Davis<\/p>\n\n\n\n<p>The Astrophysical Journal, Volume 909, Number 1<br>Published: 1 March 2021<\/p>\n\n\n\n<p><a href=\"https:\/\/iopscience.iop.org\/article\/10.3847\/1538-4357\/abd725\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>LINK<\/strong><\/a><\/p>\n\n\n\n<p class=\"justify-text\">&#8220;Molybdenum isotopes measured in most individual presolar silicon carbide grains are dominated by s-process contributions from the helium intershells of asymptotic giant branch (AGB) stars. The much smaller isotopic variations in molybdenum in meteorites and their components are largely controlled by s-process enrichments or depletions relative to terrestrial composition but lie along two parallel s-process mixing lines separated by what has been suggested to be an r-process contribution. The two mixing lines are populated by carbonaceous-chondrite- and noncarbonaceous-chondrite-related meteorites (CC and NC groups, respectively). We have compared molybdenum isotopic data for presolar grains with those from meteorites and renormalized the meteorite data in a way that is consistent with s-, r-, and p-process contributions observed in presolar SiC grains. The results indicate that (1) there seems to be a fixed ratio between p- and r-process contributions in all data, (2) the dichotomy in molybdenum isotopes between the CC and NC groups can be explained by variations in the isotope makeup of the s-process contribution to the meteoritic samples, (3) this variability is similar to the variations in s-process molybdenum from different AGB stars deduced from presolar grain analyses, and (4) the larger range of isotopic compositions found in refractory inclusions is also consistent with s-process isotope variability.&#8221;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Thomas Stephan and Andrew M. Davis The Astrophysical Journal, Volume 909, Number 1Published: 1 March 2021 LINK &#8220;Molybdenum isotopes measured in most individual presolar silicon carbide grains are dominated by s-process contributions from the helium&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[9,17,7,76,57],"tags":[3273,3290,4885,4857,1853,5313,5787],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/26613"}],"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=26613"}],"version-history":[{"count":2,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/26613\/revisions"}],"predecessor-version":[{"id":26615,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/26613\/revisions\/26615"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=26613"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=26613"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=26613"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}