{"record_type":"pith_number_record","schema_url":"https://pith.science/schemas/pith-number/v1.json","pith_number":"pith:2008:DMQPZNUDKYCQ7XGZBOP327KY66","short_pith_number":"pith:DMQPZNUD","schema_version":"1.0","canonical_sha256":"1b20fcb68356050fdcd90b9fbd7d58f7aa002d2065f651dca70f4460075f3f5a","source":{"kind":"arxiv","id":"0807.1925","version":4},"attestation_state":"computed","paper":{"title":"Uncovering Extremely Metal-Poor Stars in the Milky Way's Ultra-Faint Dwarf Spheroidal Satellite Galaxies","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph","authors_text":"(2) California Institute of Technology, (3) Yale University, (4) University of Texas Austin/McDonald Observatory), Anna Frebel (4) ((1) University of California Santa Cruz/Lick Observatory, Evan N. Kirby (1), Joshua D. Simon (2), Marla Geha (3), Puragra Guhathakurta (1)","submitted_at":"2008-07-14T19:40:25Z","abstract_excerpt":"We present new metallicity measurements for 298 individual red giant branch stars in eight of the least luminous dwarf spheroidal galaxies (dSphs) in the Milky Way (MW) system. Our technique is based on medium resolution Keck/DEIMOS spectroscopy coupled with spectral synthesis. We present the first spectroscopic metallicities at [Fe/H] < -3.0 of stars in a dwarf galaxy, with individual stellar metallicities as low as [Fe/H] = -3.3. Because our [Fe/H] measurements are not tied to empirical metallicity calibrators and are sensitive to arbitrarily low metallicities, we are able to probe this extr"},"verification_status":{"content_addressed":true,"pith_receipt":true,"author_attested":false,"weak_author_claims":0,"strong_author_claims":0,"externally_anchored":false,"storage_verified":false,"citation_signatures":0,"replication_records":0,"graph_snapshot":true,"references_resolved":false,"formal_links_present":false},"canonical_record":{"source":{"id":"0807.1925","kind":"arxiv","version":4},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph","submitted_at":"2008-07-14T19:40:25Z","cross_cats_sorted":[],"title_canon_sha256":"556f455c90cf8a85f6155a0e8922b6c79095e0bfcbcb6463745f24308b5c6194","abstract_canon_sha256":"78e77b86a1f721473d4e18220ae83e8877c8a62ba36f879698d4bd24b0addbbd"},"schema_version":"1.0"},"receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T04:38:17.527538Z","signature_b64":"hAKPF/Mxz2O7b08E1LgC6BibvLablH54TpakOW9OJcS3TE5Mbtr9yrc4izPMANzb+1qg0iSUNXdLIaBO0n/OBg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"1b20fcb68356050fdcd90b9fbd7d58f7aa002d2065f651dca70f4460075f3f5a","last_reissued_at":"2026-05-18T04:38:17.526998Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T04:38:17.526998Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"graph_snapshot":{"paper":{"title":"Uncovering Extremely Metal-Poor Stars in the Milky Way's Ultra-Faint Dwarf Spheroidal Satellite Galaxies","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph","authors_text":"(2) California Institute of Technology, (3) Yale University, (4) University of Texas Austin/McDonald Observatory), Anna Frebel (4) ((1) University of California Santa Cruz/Lick Observatory, Evan N. Kirby (1), Joshua D. Simon (2), Marla Geha (3), Puragra Guhathakurta (1)","submitted_at":"2008-07-14T19:40:25Z","abstract_excerpt":"We present new metallicity measurements for 298 individual red giant branch stars in eight of the least luminous dwarf spheroidal galaxies (dSphs) in the Milky Way (MW) system. Our technique is based on medium resolution Keck/DEIMOS spectroscopy coupled with spectral synthesis. We present the first spectroscopic metallicities at [Fe/H] < -3.0 of stars in a dwarf galaxy, with individual stellar metallicities as low as [Fe/H] = -3.3. Because our [Fe/H] measurements are not tied to empirical metallicity calibrators and are sensitive to arbitrarily low metallicities, we are able to probe this extr"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0807.1925","kind":"arxiv","version":4},"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"},"aliases":[{"alias_kind":"arxiv","alias_value":"0807.1925","created_at":"2026-05-18T04:38:17.527080+00:00"},{"alias_kind":"arxiv_version","alias_value":"0807.1925v4","created_at":"2026-05-18T04:38:17.527080+00:00"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.0807.1925","created_at":"2026-05-18T04:38:17.527080+00:00"},{"alias_kind":"pith_short_12","alias_value":"DMQPZNUDKYCQ","created_at":"2026-05-18T12:25:57.157939+00:00"},{"alias_kind":"pith_short_16","alias_value":"DMQPZNUDKYCQ7XGZ","created_at":"2026-05-18T12:25:57.157939+00:00"},{"alias_kind":"pith_short_8","alias_value":"DMQPZNUD","created_at":"2026-05-18T12:25:57.157939+00:00"}],"events":[],"event_summary":{},"paper_claims":[],"inbound_citations":{"count":0,"internal_anchor_count":0,"sample":[]},"formal_canon":{"evidence_count":0,"sample":[],"anchors":[]},"links":{"html":"https://pith.science/pith/DMQPZNUDKYCQ7XGZBOP327KY66","json":"https://pith.science/pith/DMQPZNUDKYCQ7XGZBOP327KY66.json","graph_json":"https://pith.science/api/pith-number/DMQPZNUDKYCQ7XGZBOP327KY66/graph.json","events_json":"https://pith.science/api/pith-number/DMQPZNUDKYCQ7XGZBOP327KY66/events.json","paper":"https://pith.science/paper/DMQPZNUD"},"agent_actions":{"view_html":"https://pith.science/pith/DMQPZNUDKYCQ7XGZBOP327KY66","download_json":"https://pith.science/pith/DMQPZNUDKYCQ7XGZBOP327KY66.json","view_paper":"https://pith.science/paper/DMQPZNUD","resolve_alias":"https://pith.science/api/pith-number/resolve?arxiv=0807.1925&json=true","fetch_graph":"https://pith.science/api/pith-number/DMQPZNUDKYCQ7XGZBOP327KY66/graph.json","fetch_events":"https://pith.science/api/pith-number/DMQPZNUDKYCQ7XGZBOP327KY66/events.json","actions":{"anchor_timestamp":"https://pith.science/pith/DMQPZNUDKYCQ7XGZBOP327KY66/action/timestamp_anchor","attest_storage":"https://pith.science/pith/DMQPZNUDKYCQ7XGZBOP327KY66/action/storage_attestation","attest_author":"https://pith.science/pith/DMQPZNUDKYCQ7XGZBOP327KY66/action/author_attestation","sign_citation":"https://pith.science/pith/DMQPZNUDKYCQ7XGZBOP327KY66/action/citation_signature","submit_replication":"https://pith.science/pith/DMQPZNUDKYCQ7XGZBOP327KY66/action/replication_record"}},"created_at":"2026-05-18T04:38:17.527080+00:00","updated_at":"2026-05-18T04:38:17.527080+00:00"}