{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2018:5WY54NKMSA4RXHILSBWBV6XWKR","short_pith_number":"pith:5WY54NKM","canonical_record":{"source":{"id":"1807.06486","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.SR","submitted_at":"2018-07-17T15:09:22Z","cross_cats_sorted":["astro-ph.GA"],"title_canon_sha256":"1b5d7bcf571560eca93beda9ff4ee286d72ec560523d5763cb7c69dcb259f512","abstract_canon_sha256":"a603ffc5bb86d82987ee572fce476859c7b532b5dcd4b3ebc88c662a88a5e5da"},"schema_version":"1.0"},"canonical_sha256":"edb1de354c90391b9d0b906c1afaf6546027b3d457ebe437d6d25374fbec0d87","source":{"kind":"arxiv","id":"1807.06486","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1807.06486","created_at":"2026-05-18T00:09:10Z"},{"alias_kind":"arxiv_version","alias_value":"1807.06486v1","created_at":"2026-05-18T00:09:10Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1807.06486","created_at":"2026-05-18T00:09:10Z"},{"alias_kind":"pith_short_12","alias_value":"5WY54NKMSA4R","created_at":"2026-05-18T12:32:08Z"},{"alias_kind":"pith_short_16","alias_value":"5WY54NKMSA4RXHIL","created_at":"2026-05-18T12:32:08Z"},{"alias_kind":"pith_short_8","alias_value":"5WY54NKM","created_at":"2026-05-18T12:32:08Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2018:5WY54NKMSA4RXHILSBWBV6XWKR","target":"record","payload":{"canonical_record":{"source":{"id":"1807.06486","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.SR","submitted_at":"2018-07-17T15:09:22Z","cross_cats_sorted":["astro-ph.GA"],"title_canon_sha256":"1b5d7bcf571560eca93beda9ff4ee286d72ec560523d5763cb7c69dcb259f512","abstract_canon_sha256":"a603ffc5bb86d82987ee572fce476859c7b532b5dcd4b3ebc88c662a88a5e5da"},"schema_version":"1.0"},"canonical_sha256":"edb1de354c90391b9d0b906c1afaf6546027b3d457ebe437d6d25374fbec0d87","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T00:09:10.795373Z","signature_b64":"f1mbcW6Q9iZVqGoti/rAppxrMpWxyVzS7wGl+f7NcrrQIGjt8XikYkzdVXDyuhAKb0BIs/J0pBvC/6vNZCWjAQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"edb1de354c90391b9d0b906c1afaf6546027b3d457ebe437d6d25374fbec0d87","last_reissued_at":"2026-05-18T00:09:10.794712Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T00:09:10.794712Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1807.06486","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":"2026-05-18T00:09:10Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"RdRslzOwY6EkqJKk7P1XRng6/fPTu66a7fsvoJ+4yNyr/cHkdPSwmQZhAMZZx9kFc+IDFs4jEXd7SuhFzNA1AQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-27T11:29:52.849302Z"},"content_sha256":"12d0286d9fa1b014f2dc296d853f0b102da651474dc78009065de085c137c40a","schema_version":"1.0","event_id":"sha256:12d0286d9fa1b014f2dc296d853f0b102da651474dc78009065de085c137c40a"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2018:5WY54NKMSA4RXHILSBWBV6XWKR","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Massive stars in the hinterland of the young cluster, Westerlund 2","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":["astro-ph.GA"],"primary_cat":"astro-ph.SR","authors_text":"A. Herrero, J. E. Drew, M. Mohr-Smith, M. Monguio, N. J. Wright, R. Napiwotzki, T. Kupfer","submitted_at":"2018-07-17T15:09:22Z","abstract_excerpt":"An unsettled question concerning the formation and distribution of massive stars is whether they must be born in massive clusters and, if found in less dense environments, whether they must have migrated there. With the advent of wide-area digital photometric surveys, it is now possible to identify massive stars away from prominent Galactic clusters without bias. In this study we consider 40 candidate OB stars found in the field around the young massive cluster, Westerlund 2, by Mohr-Smith et al (2017): these are located inside a box of 1.5x1.5 square degrees and are selected on the basis of t"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1807.06486","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":"2026-05-18T00:09:10Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"CmZHLwxZhsmAFW/WD2jldiTB1iMmVyNq6yAYtPFc9VaJWiTXv/p+5Lgt6lIlVGKSeFHHDesSeGFlzmmmfnUzAw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-27T11:29:52.849929Z"},"content_sha256":"7c9df34062def5f2b11738e2d803f0ba93d29a238fe9b50b45d7ed4ac30c5c88","schema_version":"1.0","event_id":"sha256:7c9df34062def5f2b11738e2d803f0ba93d29a238fe9b50b45d7ed4ac30c5c88"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/5WY54NKMSA4RXHILSBWBV6XWKR/bundle.json","state_url":"https://pith.science/pith/5WY54NKMSA4RXHILSBWBV6XWKR/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/5WY54NKMSA4RXHILSBWBV6XWKR/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":"2026-05-27T11:29:52Z","links":{"resolver":"https://pith.science/pith/5WY54NKMSA4RXHILSBWBV6XWKR","bundle":"https://pith.science/pith/5WY54NKMSA4RXHILSBWBV6XWKR/bundle.json","state":"https://pith.science/pith/5WY54NKMSA4RXHILSBWBV6XWKR/state.json","well_known_bundle":"https://pith.science/.well-known/pith/5WY54NKMSA4RXHILSBWBV6XWKR/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2018:5WY54NKMSA4RXHILSBWBV6XWKR","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":"a603ffc5bb86d82987ee572fce476859c7b532b5dcd4b3ebc88c662a88a5e5da","cross_cats_sorted":["astro-ph.GA"],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.SR","submitted_at":"2018-07-17T15:09:22Z","title_canon_sha256":"1b5d7bcf571560eca93beda9ff4ee286d72ec560523d5763cb7c69dcb259f512"},"schema_version":"1.0","source":{"id":"1807.06486","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1807.06486","created_at":"2026-05-18T00:09:10Z"},{"alias_kind":"arxiv_version","alias_value":"1807.06486v1","created_at":"2026-05-18T00:09:10Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1807.06486","created_at":"2026-05-18T00:09:10Z"},{"alias_kind":"pith_short_12","alias_value":"5WY54NKMSA4R","created_at":"2026-05-18T12:32:08Z"},{"alias_kind":"pith_short_16","alias_value":"5WY54NKMSA4RXHIL","created_at":"2026-05-18T12:32:08Z"},{"alias_kind":"pith_short_8","alias_value":"5WY54NKM","created_at":"2026-05-18T12:32:08Z"}],"graph_snapshots":[{"event_id":"sha256:7c9df34062def5f2b11738e2d803f0ba93d29a238fe9b50b45d7ed4ac30c5c88","target":"graph","created_at":"2026-05-18T00:09:10Z","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":"An unsettled question concerning the formation and distribution of massive stars is whether they must be born in massive clusters and, if found in less dense environments, whether they must have migrated there. With the advent of wide-area digital photometric surveys, it is now possible to identify massive stars away from prominent Galactic clusters without bias. In this study we consider 40 candidate OB stars found in the field around the young massive cluster, Westerlund 2, by Mohr-Smith et al (2017): these are located inside a box of 1.5x1.5 square degrees and are selected on the basis of t","authors_text":"A. Herrero, J. E. Drew, M. Mohr-Smith, M. Monguio, N. J. Wright, R. Napiwotzki, T. Kupfer","cross_cats":["astro-ph.GA"],"headline":"","license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.SR","submitted_at":"2018-07-17T15:09:22Z","title":"Massive stars in the hinterland of the young cluster, Westerlund 2"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1807.06486","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":"sha256:12d0286d9fa1b014f2dc296d853f0b102da651474dc78009065de085c137c40a","target":"record","created_at":"2026-05-18T00:09:10Z","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":"a603ffc5bb86d82987ee572fce476859c7b532b5dcd4b3ebc88c662a88a5e5da","cross_cats_sorted":["astro-ph.GA"],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.SR","submitted_at":"2018-07-17T15:09:22Z","title_canon_sha256":"1b5d7bcf571560eca93beda9ff4ee286d72ec560523d5763cb7c69dcb259f512"},"schema_version":"1.0","source":{"id":"1807.06486","kind":"arxiv","version":1}},"canonical_sha256":"edb1de354c90391b9d0b906c1afaf6546027b3d457ebe437d6d25374fbec0d87","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"edb1de354c90391b9d0b906c1afaf6546027b3d457ebe437d6d25374fbec0d87","first_computed_at":"2026-05-18T00:09:10.794712Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T00:09:10.794712Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"f1mbcW6Q9iZVqGoti/rAppxrMpWxyVzS7wGl+f7NcrrQIGjt8XikYkzdVXDyuhAKb0BIs/J0pBvC/6vNZCWjAQ==","signature_status":"signed_v1","signed_at":"2026-05-18T00:09:10.795373Z","signed_message":"canonical_sha256_bytes"},"source_id":"1807.06486","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:12d0286d9fa1b014f2dc296d853f0b102da651474dc78009065de085c137c40a","sha256:7c9df34062def5f2b11738e2d803f0ba93d29a238fe9b50b45d7ed4ac30c5c88"],"state_sha256":"fbfed67fef59f11934605ab65b4b5a74a751adc2601d4a454fa396cb9b6daac3"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"K9qUMUux+60ySC6ul5SX0PMqOPMcUg25tG4eLObGfydxgpYi3RLxBK5uxtBlEhZ+UK8OFLotHS0lWruI2md2Bw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-27T11:29:52.854036Z","bundle_sha256":"0f84129f72720eebc9a7859fe10950747f1f3a662f25a294473224e93002415d"}}