{"record_type":"pith_number_record","schema_url":"https://pith.science/schemas/pith-number/v1.json","pith_number":"pith:2019:IPLOEMVHX54VCWYZGBYUGHZXZU","short_pith_number":"pith:IPLOEMVH","schema_version":"1.0","canonical_sha256":"43d6e232a7bf79515b193071431f37cd254844e645c8cfae8e76734e8df28331","source":{"kind":"arxiv","id":"1901.02466","version":1},"attestation_state":"computed","paper":{"title":"Ongoing star formation at the outskirts of Sextans A: Spectroscopic detection of early-O type stars","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.SR"],"primary_cat":"astro-ph.GA","authors_text":"(2) Instituto de Astrof\\'isica de Canarias, 3), (3) Dpto. de Astrof\\'isica, (4) Dpto. de F\\'isica de la Tierra y Astrof\\'isica, Artemio Herrero (2, Francisco Najarro (1), In\\'es Camacho (2, Marta Lorenzo (4). ((1) Centro de Astrobiolog\\'ia CSIC-INTA, Miriam Garcia (1), Universidad Complutense de Madrid), Universidad de La Laguna","submitted_at":"2019-01-08T19:00:08Z","abstract_excerpt":"With both nebular- and stellar-derived abundances of $\\lesssim$ 1/10 Zsun and low foreground extinction, Sextans A is a prime candidate to replace the Small Magellanic Cloud as reservoir of metal-poor massive stars and reference to study the metal-poor Universe. We report the discovery of two early-O type stars in Sextans A, the earliest O-stars with metallicity < 1/7 Zsun known to date, and two additional O9 stars. Colour-excess estimates towards individual targets, enabled by spectral typing, manifest that internal reddening is neither uniform nor negligible. The four targets define a new re"},"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":"1901.02466","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.GA","submitted_at":"2019-01-08T19:00:08Z","cross_cats_sorted":["astro-ph.SR"],"title_canon_sha256":"240347b5f5d791d6448a086da265d1d842432e2bd301c2809dc66c510304a6b6","abstract_canon_sha256":"e4cdd23f7d996843a7c1d2113954ac64424faad1092f04e74c2e95ab1a229ec3"},"schema_version":"1.0"},"receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-17T23:56:40.465761Z","signature_b64":"Vrqf5VNYRLk717rvTKnPRgpDolpsrQ9Bnbdz6bb8ci1h5fqI0sydRhKIw4AXXsdR65WfZ1E+iqjI4UW9CyUnAA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"43d6e232a7bf79515b193071431f37cd254844e645c8cfae8e76734e8df28331","last_reissued_at":"2026-05-17T23:56:40.465089Z","signature_status":"signed_v1","first_computed_at":"2026-05-17T23:56:40.465089Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"graph_snapshot":{"paper":{"title":"Ongoing star formation at the outskirts of Sextans A: Spectroscopic detection of early-O type stars","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.SR"],"primary_cat":"astro-ph.GA","authors_text":"(2) Instituto de Astrof\\'isica de Canarias, 3), (3) Dpto. de Astrof\\'isica, (4) Dpto. de F\\'isica de la Tierra y Astrof\\'isica, Artemio Herrero (2, Francisco Najarro (1), In\\'es Camacho (2, Marta Lorenzo (4). ((1) Centro de Astrobiolog\\'ia CSIC-INTA, Miriam Garcia (1), Universidad Complutense de Madrid), Universidad de La Laguna","submitted_at":"2019-01-08T19:00:08Z","abstract_excerpt":"With both nebular- and stellar-derived abundances of $\\lesssim$ 1/10 Zsun and low foreground extinction, Sextans A is a prime candidate to replace the Small Magellanic Cloud as reservoir of metal-poor massive stars and reference to study the metal-poor Universe. We report the discovery of two early-O type stars in Sextans A, the earliest O-stars with metallicity < 1/7 Zsun known to date, and two additional O9 stars. Colour-excess estimates towards individual targets, enabled by spectral typing, manifest that internal reddening is neither uniform nor negligible. The four targets define a new re"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1901.02466","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"},"aliases":[{"alias_kind":"arxiv","alias_value":"1901.02466","created_at":"2026-05-17T23:56:40.465193+00:00"},{"alias_kind":"arxiv_version","alias_value":"1901.02466v1","created_at":"2026-05-17T23:56:40.465193+00:00"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1901.02466","created_at":"2026-05-17T23:56:40.465193+00:00"},{"alias_kind":"pith_short_12","alias_value":"IPLOEMVHX54V","created_at":"2026-05-18T12:33:18.533446+00:00"},{"alias_kind":"pith_short_16","alias_value":"IPLOEMVHX54VCWYZ","created_at":"2026-05-18T12:33:18.533446+00:00"},{"alias_kind":"pith_short_8","alias_value":"IPLOEMVH","created_at":"2026-05-18T12:33:18.533446+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/IPLOEMVHX54VCWYZGBYUGHZXZU","json":"https://pith.science/pith/IPLOEMVHX54VCWYZGBYUGHZXZU.json","graph_json":"https://pith.science/api/pith-number/IPLOEMVHX54VCWYZGBYUGHZXZU/graph.json","events_json":"https://pith.science/api/pith-number/IPLOEMVHX54VCWYZGBYUGHZXZU/events.json","paper":"https://pith.science/paper/IPLOEMVH"},"agent_actions":{"view_html":"https://pith.science/pith/IPLOEMVHX54VCWYZGBYUGHZXZU","download_json":"https://pith.science/pith/IPLOEMVHX54VCWYZGBYUGHZXZU.json","view_paper":"https://pith.science/paper/IPLOEMVH","resolve_alias":"https://pith.science/api/pith-number/resolve?arxiv=1901.02466&json=true","fetch_graph":"https://pith.science/api/pith-number/IPLOEMVHX54VCWYZGBYUGHZXZU/graph.json","fetch_events":"https://pith.science/api/pith-number/IPLOEMVHX54VCWYZGBYUGHZXZU/events.json","actions":{"anchor_timestamp":"https://pith.science/pith/IPLOEMVHX54VCWYZGBYUGHZXZU/action/timestamp_anchor","attest_storage":"https://pith.science/pith/IPLOEMVHX54VCWYZGBYUGHZXZU/action/storage_attestation","attest_author":"https://pith.science/pith/IPLOEMVHX54VCWYZGBYUGHZXZU/action/author_attestation","sign_citation":"https://pith.science/pith/IPLOEMVHX54VCWYZGBYUGHZXZU/action/citation_signature","submit_replication":"https://pith.science/pith/IPLOEMVHX54VCWYZGBYUGHZXZU/action/replication_record"}},"created_at":"2026-05-17T23:56:40.465193+00:00","updated_at":"2026-05-17T23:56:40.465193+00:00"}