{"record_type":"pith_number_record","schema_url":"https://pith.science/schemas/pith-number/v1.json","pith_number":"pith:2001:H7YRMOLJCGPVN4VHV5F6D5QUTR","short_pith_number":"pith:H7YRMOLJ","schema_version":"1.0","canonical_sha256":"3ff1163969119f56f2a7af4be1f6149c763d8cac948307aed38bc605d1367302","source":{"kind":"arxiv","id":"astro-ph/0105448","version":1},"attestation_state":"computed","paper":{"title":"Hydrogen-poor planetary nebulae","license":"","headline":"","cross_cats":[],"primary_cat":"astro-ph","authors_text":"Albert A. Zijlstra","submitted_at":"2001-05-25T10:25:17Z","abstract_excerpt":"Five planetary nebulae are known to show hydrogen-poor material near the central star. In the case of A58, this gas was ejected following a late thermal pulse similar to Sakurai's Object. In this paper I will review these five objects. One of them, IRAS 18333$-$2357, may not be a true PN. I will show that there is a strong case for a relation to the [WC] stars and their relatives, the weak emission-line stars. The surface abundances of the [WC] stars are explained via diffuse overshoot into the helium layer. The hydrogen-poor PNe do not support this: their abundances indicate a change of abund"},"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":"astro-ph/0105448","kind":"arxiv","version":1},"metadata":{"license":"","primary_cat":"astro-ph","submitted_at":"2001-05-25T10:25:17Z","cross_cats_sorted":[],"title_canon_sha256":"f402a34149086ba67a9b34174c3f24fd8a1f5dcc2c6b162029e20a16136a259a","abstract_canon_sha256":"699d22b24d74ea6af29304eb58dbd4b9e4dce50a79d79fa2e7c2394e7e3c64c6"},"schema_version":"1.0"},"receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-04T14:11:16.654983Z","signature_b64":"Fj55Rx/quu/PS5KXnmsGlJn2+WaBwphteDxFG5v5euv1uhW/Qf6TqaTv2e42V4hYp27VZ4gCzSKbc7l87l7TBw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"3ff1163969119f56f2a7af4be1f6149c763d8cac948307aed38bc605d1367302","last_reissued_at":"2026-07-04T14:11:16.654576Z","signature_status":"signed_v1","first_computed_at":"2026-07-04T14:11:16.654576Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"graph_snapshot":{"paper":{"title":"Hydrogen-poor planetary nebulae","license":"","headline":"","cross_cats":[],"primary_cat":"astro-ph","authors_text":"Albert A. Zijlstra","submitted_at":"2001-05-25T10:25:17Z","abstract_excerpt":"Five planetary nebulae are known to show hydrogen-poor material near the central star. In the case of A58, this gas was ejected following a late thermal pulse similar to Sakurai's Object. In this paper I will review these five objects. One of them, IRAS 18333$-$2357, may not be a true PN. I will show that there is a strong case for a relation to the [WC] stars and their relatives, the weak emission-line stars. The surface abundances of the [WC] stars are explained via diffuse overshoot into the helium layer. The hydrogen-poor PNe do not support this: their abundances indicate a change of abund"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"astro-ph/0105448","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":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/astro-ph/0105448/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"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":"astro-ph/0105448","created_at":"2026-07-04T14:11:16.654636+00:00"},{"alias_kind":"arxiv_version","alias_value":"astro-ph/0105448v1","created_at":"2026-07-04T14:11:16.654636+00:00"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.astro-ph/0105448","created_at":"2026-07-04T14:11:16.654636+00:00"},{"alias_kind":"pith_short_12","alias_value":"H7YRMOLJCGPV","created_at":"2026-07-04T14:11:16.654636+00:00"},{"alias_kind":"pith_short_16","alias_value":"H7YRMOLJCGPVN4VH","created_at":"2026-07-04T14:11:16.654636+00:00"},{"alias_kind":"pith_short_8","alias_value":"H7YRMOLJ","created_at":"2026-07-04T14:11:16.654636+00:00"}],"events":[],"event_summary":{},"paper_claims":[],"inbound_citations":{"count":1,"internal_anchor_count":1,"sample":[{"citing_arxiv_id":"2412.11721","citing_title":"Infrared properties of Planetary Nebulae with PG1159 central stars","ref_index":2002,"is_internal_anchor":true}]},"formal_canon":{"evidence_count":0,"sample":[],"anchors":[]},"links":{"html":"https://pith.science/pith/H7YRMOLJCGPVN4VHV5F6D5QUTR","json":"https://pith.science/pith/H7YRMOLJCGPVN4VHV5F6D5QUTR.json","graph_json":"https://pith.science/api/pith-number/H7YRMOLJCGPVN4VHV5F6D5QUTR/graph.json","events_json":"https://pith.science/api/pith-number/H7YRMOLJCGPVN4VHV5F6D5QUTR/events.json","paper":"https://pith.science/paper/H7YRMOLJ"},"agent_actions":{"view_html":"https://pith.science/pith/H7YRMOLJCGPVN4VHV5F6D5QUTR","download_json":"https://pith.science/pith/H7YRMOLJCGPVN4VHV5F6D5QUTR.json","view_paper":"https://pith.science/paper/H7YRMOLJ","resolve_alias":"https://pith.science/api/pith-number/resolve?arxiv=astro-ph/0105448&json=true","fetch_graph":"https://pith.science/api/pith-number/H7YRMOLJCGPVN4VHV5F6D5QUTR/graph.json","fetch_events":"https://pith.science/api/pith-number/H7YRMOLJCGPVN4VHV5F6D5QUTR/events.json","actions":{"anchor_timestamp":"https://pith.science/pith/H7YRMOLJCGPVN4VHV5F6D5QUTR/action/timestamp_anchor","attest_storage":"https://pith.science/pith/H7YRMOLJCGPVN4VHV5F6D5QUTR/action/storage_attestation","attest_author":"https://pith.science/pith/H7YRMOLJCGPVN4VHV5F6D5QUTR/action/author_attestation","sign_citation":"https://pith.science/pith/H7YRMOLJCGPVN4VHV5F6D5QUTR/action/citation_signature","submit_replication":"https://pith.science/pith/H7YRMOLJCGPVN4VHV5F6D5QUTR/action/replication_record"}},"created_at":"2026-07-04T14:11:16.654636+00:00","updated_at":"2026-07-04T14:11:16.654636+00:00"}