{"id":4384,"date":"2026-03-03T10:28:02","date_gmt":"2026-03-03T13:28:02","guid":{"rendered":"https:\/\/www.ufrgs.br\/astronomia\/?post_type=tribe_events&#038;p=4384"},"modified":"2026-04-08T14:51:52","modified_gmt":"2026-04-08T17:51:52","slug":"isotopic-abundances-in-globular-clusters-as-tests-of-stellar-nucleosynthesis-madeleine-mckenzie-carnegie-observatories","status":"publish","type":"tribe_events","link":"https:\/\/www.ufrgs.br\/astronomia\/en\/event\/isotopic-abundances-in-globular-clusters-as-tests-of-stellar-nucleosynthesis-madeleine-mckenzie-carnegie-observatories\/","title":{"rendered":"Isotopic Abundances in Globular Clusters as Tests of Stellar Nucleosynthesis &#8211; Madeleine McKenzie (Carnegie Observatories)"},"content":{"rendered":"<strong>Abstract<\/strong><br \/>\nMagnesium isotope ratios provide a powerful probe of the origin of chemical anomalies in globular clusters. Although globular clusters were once thought to contain stars of a single chemical composition, we now know that many host multiple stellar populations with distinct abundance patterns. These variations point to high-temperature nuclear processing in an earlier generation of stars, but the nature of those stars and the enrichment mechanisms remain uncertain. In this talk, I present a high-precision spectroscopic analysis of magnesium isotope ratios in globular cluster stars. We find that stars enriched in nitrogen, sodium, and aluminium also show enhanced ^26Mg\/^24Mg, but not ^25Mg\/^24Mg, revealing a surprising isotopic pattern that is difficult to reproduce in current models. We also find no clear isotopic difference between stars with and without enhancements in slow neutron-capture elements. Together, these results provide new insight into the stellar sources and nuclear processes that shaped the chemistry of globular clusters.<\/p>\n<p>&nbsp;<\/p>\n<p dir=\"ltr\"><strong>Link<\/strong> <strong>Zoom<\/strong>: <a href=\"https:\/\/zoom.us\/j\/94830401725?pwd=jtp6J5W9ZwGQxYOAx86aVfeTYmBsr4.1\" target=\"_blank\" rel=\"noopener\" data-saferedirecturl=\"https:\/\/www.google.com\/url?q=https:\/\/zoom.us\/j\/94830401725?pwd%3Djtp6J5W9ZwGQxYOAx86aVfeTYmBsr4.1&amp;source=gmail&amp;ust=1775218927138000&amp;usg=AOvVaw3n0meWhsKTf8OtOIxPxjAC\">https:\/\/zoom.us\/j\/94830401725?<wbr \/>pwd=<wbr \/>jtp6J5W9ZwGQxYOAx86aVfeTYmBsr4<wbr \/>.1<\/a><\/p>\n<p dir=\"ltr\"><strong>Meeting<\/strong> <strong>ID<\/strong>: 948 3040 1725<\/p>\n<p dir=\"ltr\"><strong>Password<\/strong>: 182015<\/p>\n<p dir=\"ltr\"><strong>Link YouTube<\/strong>: <a href=\"https:\/\/youtube.com\/live\/oUGn_jNBD4U\" target=\"_blank\" rel=\"noopener\" data-saferedirecturl=\"https:\/\/www.google.com\/url?q=https:\/\/youtube.com\/live\/oUGn_jNBD4U&amp;source=gmail&amp;ust=1775218927138000&amp;usg=AOvVaw2cKWJhdQzwPB_JmRrsfS3P\">https:\/\/youtube.com\/live\/oUGn_<wbr \/>jNBD4U<\/a><\/p>","protected":false},"excerpt":{"rendered":"<p>Abstract Magnesium isotope ratios provide a powerful probe of the origin of chemical anomalies in globular clusters. Although globular clusters were once thought to contain stars of a single chemical composition, we now know that many host multiple stellar populations with distinct abundance patterns. These variations point to high-temperature nuclear processing in an earlier generation [&hellip;]<\/p>\n","protected":false},"author":29,"featured_media":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_tribe_events_status":"","_tribe_events_status_reason":""},"tags":[],"tribe_events_cat":[],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.ufrgs.br\/astronomia\/en\/wp-json\/wp\/v2\/tribe_events\/4384"}],"collection":[{"href":"https:\/\/www.ufrgs.br\/astronomia\/en\/wp-json\/wp\/v2\/tribe_events"}],"about":[{"href":"https:\/\/www.ufrgs.br\/astronomia\/en\/wp-json\/wp\/v2\/types\/tribe_events"}],"author":[{"embeddable":true,"href":"https:\/\/www.ufrgs.br\/astronomia\/en\/wp-json\/wp\/v2\/users\/29"}],"replies":[{"embeddable":true,"href":"https:\/\/www.ufrgs.br\/astronomia\/en\/wp-json\/wp\/v2\/comments?post=4384"}],"version-history":[{"count":4,"href":"https:\/\/www.ufrgs.br\/astronomia\/en\/wp-json\/wp\/v2\/tribe_events\/4384\/revisions"}],"predecessor-version":[{"id":4427,"href":"https:\/\/www.ufrgs.br\/astronomia\/en\/wp-json\/wp\/v2\/tribe_events\/4384\/revisions\/4427"}],"wp:attachment":[{"href":"https:\/\/www.ufrgs.br\/astronomia\/en\/wp-json\/wp\/v2\/media?parent=4384"}],"wp:term":[{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ufrgs.br\/astronomia\/en\/wp-json\/wp\/v2\/tags?post=4384"},{"taxonomy":"tribe_events_cat","embeddable":true,"href":"https:\/\/www.ufrgs.br\/astronomia\/en\/wp-json\/wp\/v2\/tribe_events_cat?post=4384"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}