{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"28be2d92163009e230df74a05d4c2117417f9992fdee91ff92e11a52021e0660","created":"2026-10-03T07:17:55Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["2b0d5d2ed8e499603637f1fc0a3ee48b7ad5d64e04786e66086c6d908745ec96","5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"850b19de13df205ca1faeb566e9aefbc9488c24910915874399c6cb5010983e3","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"yes-no","assisted_by":[],"external_id":"astro.r-process-sites.early-enrichment","kind":"well-posed","literature_status":"contested","n":"1","parents":[{"note":"","parent_revision":"2b0d5d2ed8e499603637f1fc0a3ee48b7ad5d64e04786e66086c6d908745ec96","relation":"special_case"}],"plain":"Some very old stars already contain r-process elements, yet merging neutron stars need time to spiral together.","posed_since":"","precise":"Determine whether merger delay-time distributions (minimum ~10 Myr, $\\mathrm{d}N/\\mathrm{d}t \\sim t^{-1}$) with natal kicks and inhomogeneous mixing reproduce r-process enrichment in ultra-faint dwarf galaxies such as Reticulum II and the decline of $[\\mathrm{Eu}/\\mathrm{Fe}]$ at $[\\mathrm{Fe}/\\mathrm{H}] > -1$ in the Galactic disk, or whether a prompt source is required. Answer: yes or no from galactic chemical evolution models.","problem_ref":null,"references":"","settled_by":"Chemical-evolution models with measured delay times and kicks fit to large samples of Eu abundances in dwarf galaxies and the disk, with and without a prompt source.","status_note":"","title":"Can neutron-star mergers explain r-process elements in the oldest stars?","topic_ref":"629fb53d8771f28ff08120cbd19ad49c2c6fdc9fd60798b0f0a9704b24fc3033"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"cd864ee18f5fc18c35cc9b431763763010fe82cc549dfe3bb07cf953528793a6","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"d3368cb41ddcbfbc41f669747ffe331102a8fa1999ee7cf29aef922f8b5aef28","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"UoH0W8vKAHP4zULT3Fpofaw7Fn1nqULFg-ql2YvRU3kEPuFbuUpqreyJ4MaF2fHGV-JZAy2xxuFwn5Lka7kmDw"},"schema":"pubphys.envelope/1"},"record_hash":"cd864ee18f5fc18c35cc9b431763763010fe82cc549dfe3bb07cf953528793a6","leaf_index":593}