{"paper":{"title":"Light Element Chemistry and the Double Red Giant Branch in the Galactic Globular Cluster NGC 288","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.SR","authors_text":"Christian I. Johnson, R. Michael Rich, Tiffany Hsyu, Young-Wook Lee","submitted_at":"2014-06-19T21:23:23Z","abstract_excerpt":"The globular cluster NGC 288 was previously reported to exhibit two distinct red giant branches (RGBs) in the narrow-band Calcium (HK) and Str\\\"omgren b and y band passes. In order to investigate this phenomenon further, we obtained moderate resolution (R$\\sim$18,000) spectra of 27 RGB stars in NGC 288 with the Hydra multifiber spectrograph on the Blanco 4m telescope at Cerro Tololo Inter-American Observatory. From these data we derive iron ($\\langle$[Fe/H]$\\rangle$=-1.19; $\\sigma$=0.12), oxygen ($\\langle$[O/Fe]$\\rangle$=$+$0.25; $\\sigma$=0.13), and sodium ($\\langle$[Na/Fe]$\\rangle$=$+$0.15; $"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1406.5220","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}