{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2013:6XJREVTYSJFEG3T33UF65EA5OK","short_pith_number":"pith:6XJREVTY","canonical_record":{"source":{"id":"1307.5980","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.SR","submitted_at":"2013-07-23T08:58:51Z","cross_cats_sorted":[],"title_canon_sha256":"181f04a41a2fe2713985e09aa29a0444f3bf942ccd0736748b9af896352f6528","abstract_canon_sha256":"8027368dfec8f54ebd539cac2aed898bfbac54be19a060b968cc9b169edb96e2"},"schema_version":"1.0"},"canonical_sha256":"f5d3125678924a436e7bdd0bee901d72a20243c99ceababcca6c07768b28b1ba","source":{"kind":"arxiv","id":"1307.5980","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1307.5980","created_at":"2026-05-18T01:48:41Z"},{"alias_kind":"arxiv_version","alias_value":"1307.5980v1","created_at":"2026-05-18T01:48:41Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1307.5980","created_at":"2026-05-18T01:48:41Z"},{"alias_kind":"pith_short_12","alias_value":"6XJREVTYSJFE","created_at":"2026-05-18T12:27:36Z"},{"alias_kind":"pith_short_16","alias_value":"6XJREVTYSJFEG3T3","created_at":"2026-05-18T12:27:36Z"},{"alias_kind":"pith_short_8","alias_value":"6XJREVTY","created_at":"2026-05-18T12:27:36Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2013:6XJREVTYSJFEG3T33UF65EA5OK","target":"record","payload":{"canonical_record":{"source":{"id":"1307.5980","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.SR","submitted_at":"2013-07-23T08:58:51Z","cross_cats_sorted":[],"title_canon_sha256":"181f04a41a2fe2713985e09aa29a0444f3bf942ccd0736748b9af896352f6528","abstract_canon_sha256":"8027368dfec8f54ebd539cac2aed898bfbac54be19a060b968cc9b169edb96e2"},"schema_version":"1.0"},"canonical_sha256":"f5d3125678924a436e7bdd0bee901d72a20243c99ceababcca6c07768b28b1ba","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T01:48:41.302215Z","signature_b64":"BHpYuhJoAC9nVmtTmW0pVSMwBZdmMwhQh71SzmesMu4KDxHIf4VrQMIc7D10T2FfDJZ4R1EbRingPIlGic41AA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"f5d3125678924a436e7bdd0bee901d72a20243c99ceababcca6c07768b28b1ba","last_reissued_at":"2026-05-18T01:48:41.301525Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T01:48:41.301525Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1307.5980","source_version":1,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T01:48:41Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"BVhxZKv2zXvNHxpgn1MnSjAPLviBL5GqgoFMgLo/PUyoF2DlQBCyjUuVEuW8BgeqJ5KTCj7FkI304bRq7xwEDA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-28T20:21:06.134303Z"},"content_sha256":"a1cdfdfdc9740a19fd32ce4486610ac13536e200eeffd560fcc47caa05491826","schema_version":"1.0","event_id":"sha256:a1cdfdfdc9740a19fd32ce4486610ac13536e200eeffd560fcc47caa05491826"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2013:6XJREVTYSJFEG3T33UF65EA5OK","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Hot subdwarf stars in close-up view IV. Helium abundances and the $^3$He isotopic anomaly of subdwarf B star","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.SR","authors_text":"C. Copperwheat, D. Kilkenny, D. O'Donoghue, H. Edelmann, L. Morales-Rueda, S. Geier, T. R. Marsh, U. Heber","submitted_at":"2013-07-23T08:58:51Z","abstract_excerpt":"Atmospheric parameters and helium abundances of 44 bright subdwarf B stars have been determined. More than half of our sample consists of newly discovered stars from the Edinburgh Cape survey. We showed that effective temperatures and surface gravities can be derived from high resolution echelle spectra with sufficient accuracy. Systematic uncertainties have been determined by comparing the parameters derived from the high resolution data with the ones derived from medium resolution spectra. Helium abundances have been measured with high accuracy. Besides the known correlation of helium abunda"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1307.5980","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"},"verdict_id":null},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T01:48:41Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"jY8NRx0gtz3/FAq6AE1ESW52rFOHxdFoBAm5RUCY0DWTcVGPhsUbxtlLq8WI+54fjp/Sa17oy30q9SxzydQcAw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-28T20:21:06.135049Z"},"content_sha256":"baf0962668780076c7d0e5bf9c42d9e521a6bcab1a0489eabce38e6dfe71a4d0","schema_version":"1.0","event_id":"sha256:baf0962668780076c7d0e5bf9c42d9e521a6bcab1a0489eabce38e6dfe71a4d0"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/6XJREVTYSJFEG3T33UF65EA5OK/bundle.json","state_url":"https://pith.science/pith/6XJREVTYSJFEG3T33UF65EA5OK/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/6XJREVTYSJFEG3T33UF65EA5OK/bundle.json","status":"primary"}],"public_keys":[{"key_id":"pith-v1-2026-05","algorithm":"ed25519","format":"raw","public_key_b64":"stVStoiQhXFxp4s2pdzPNoqVNBMojDU/fJ2db5S3CbM=","public_key_hex":"b2d552b68890857171a78b36a5dccf368a953413288c353f7c9d9d6f94b709b3","fingerprint_sha256_b32_first128bits":"RVFV5Z2OI2J3ZUO7ERDEBCYNKS","fingerprint_sha256_hex":"8d4b5ee74e4693bcd1df2446408b0d54","rotates_at":null,"url":"https://pith.science/pith-signing-key.json","notes":"Pith uses this Ed25519 key to sign canonical record SHA-256 digests. Verify with: ed25519_verify(public_key, message=canonical_sha256_bytes, signature=base64decode(signature_b64))."}],"merge_version":"pith-open-graph-merge-v1","built_at":"2026-05-28T20:21:06Z","links":{"resolver":"https://pith.science/pith/6XJREVTYSJFEG3T33UF65EA5OK","bundle":"https://pith.science/pith/6XJREVTYSJFEG3T33UF65EA5OK/bundle.json","state":"https://pith.science/pith/6XJREVTYSJFEG3T33UF65EA5OK/state.json","well_known_bundle":"https://pith.science/.well-known/pith/6XJREVTYSJFEG3T33UF65EA5OK/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2013:6XJREVTYSJFEG3T33UF65EA5OK","merge_version":"pith-open-graph-merge-v1","event_count":2,"valid_event_count":2,"invalid_event_count":0,"equivocation_count":0,"current":{"canonical_record":{"metadata":{"abstract_canon_sha256":"8027368dfec8f54ebd539cac2aed898bfbac54be19a060b968cc9b169edb96e2","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.SR","submitted_at":"2013-07-23T08:58:51Z","title_canon_sha256":"181f04a41a2fe2713985e09aa29a0444f3bf942ccd0736748b9af896352f6528"},"schema_version":"1.0","source":{"id":"1307.5980","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1307.5980","created_at":"2026-05-18T01:48:41Z"},{"alias_kind":"arxiv_version","alias_value":"1307.5980v1","created_at":"2026-05-18T01:48:41Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1307.5980","created_at":"2026-05-18T01:48:41Z"},{"alias_kind":"pith_short_12","alias_value":"6XJREVTYSJFE","created_at":"2026-05-18T12:27:36Z"},{"alias_kind":"pith_short_16","alias_value":"6XJREVTYSJFEG3T3","created_at":"2026-05-18T12:27:36Z"},{"alias_kind":"pith_short_8","alias_value":"6XJREVTY","created_at":"2026-05-18T12:27:36Z"}],"graph_snapshots":[{"event_id":"sha256:baf0962668780076c7d0e5bf9c42d9e521a6bcab1a0489eabce38e6dfe71a4d0","target":"graph","created_at":"2026-05-18T01:48:41Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"graph_snapshot":{"author_claims":{"count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","strong_count":0},"builder_version":"pith-number-builder-2026-05-17-v1","claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"paper":{"abstract_excerpt":"Atmospheric parameters and helium abundances of 44 bright subdwarf B stars have been determined. More than half of our sample consists of newly discovered stars from the Edinburgh Cape survey. We showed that effective temperatures and surface gravities can be derived from high resolution echelle spectra with sufficient accuracy. Systematic uncertainties have been determined by comparing the parameters derived from the high resolution data with the ones derived from medium resolution spectra. Helium abundances have been measured with high accuracy. Besides the known correlation of helium abunda","authors_text":"C. Copperwheat, D. Kilkenny, D. O'Donoghue, H. Edelmann, L. Morales-Rueda, S. Geier, T. R. Marsh, U. Heber","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.SR","submitted_at":"2013-07-23T08:58:51Z","title":"Hot subdwarf stars in close-up view IV. Helium abundances and the $^3$He isotopic anomaly of subdwarf B star"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1307.5980","kind":"arxiv","version":1},"verdict":{"created_at":null,"id":null,"model_set":{},"one_line_summary":"","pipeline_version":null,"pith_extraction_headline":"","strongest_claim":"","weakest_assumption":""}},"verdict_id":null}}],"author_attestations":[],"timestamp_anchors":[],"storage_attestations":[],"citation_signatures":[],"replication_records":[],"corrections":[],"mirror_hints":[],"record_created":{"event_id":"sha256:a1cdfdfdc9740a19fd32ce4486610ac13536e200eeffd560fcc47caa05491826","target":"record","created_at":"2026-05-18T01:48:41Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"attestation_state":"computed","canonical_record":{"metadata":{"abstract_canon_sha256":"8027368dfec8f54ebd539cac2aed898bfbac54be19a060b968cc9b169edb96e2","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.SR","submitted_at":"2013-07-23T08:58:51Z","title_canon_sha256":"181f04a41a2fe2713985e09aa29a0444f3bf942ccd0736748b9af896352f6528"},"schema_version":"1.0","source":{"id":"1307.5980","kind":"arxiv","version":1}},"canonical_sha256":"f5d3125678924a436e7bdd0bee901d72a20243c99ceababcca6c07768b28b1ba","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"f5d3125678924a436e7bdd0bee901d72a20243c99ceababcca6c07768b28b1ba","first_computed_at":"2026-05-18T01:48:41.301525Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T01:48:41.301525Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"BHpYuhJoAC9nVmtTmW0pVSMwBZdmMwhQh71SzmesMu4KDxHIf4VrQMIc7D10T2FfDJZ4R1EbRingPIlGic41AA==","signature_status":"signed_v1","signed_at":"2026-05-18T01:48:41.302215Z","signed_message":"canonical_sha256_bytes"},"source_id":"1307.5980","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:a1cdfdfdc9740a19fd32ce4486610ac13536e200eeffd560fcc47caa05491826","sha256:baf0962668780076c7d0e5bf9c42d9e521a6bcab1a0489eabce38e6dfe71a4d0"],"state_sha256":"f18c7937cb34659231a145f602894c3c1dec0475b7aceb5b405b25ba0d3e9347"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"23V4OeNLvaadeOdLbMzG4kxFgZZMJl+TCZerf+N3FZZpoERl2BhCol66uHFoadrQ7LAa1BRqSJDgSVIdlp5/Bw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-28T20:21:06.138932Z","bundle_sha256":"107d576ac16ccad2bd65c7cb3a80500a823a6bf8798b93e1573e6f56927f7887"}}