{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2021:3ZNHBJRTFY63BM4GLXC4W5KDLO","short_pith_number":"pith:3ZNHBJRT","canonical_record":{"source":{"id":"2106.02054","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.GA","submitted_at":"2021-06-03T18:00:08Z","cross_cats_sorted":["astro-ph.SR"],"title_canon_sha256":"5dee63483b052dc12e5da2f8578c99fefbfb7fcbccf0ff833cbfffbd6264c004","abstract_canon_sha256":"b09f88488a022842a4d21f1d88d0619a456205baade6af74f3a67a531aee812c"},"schema_version":"1.0"},"canonical_sha256":"de5a70a6332e3db0b3865dc5cb75435b803108ffef4c13ef78e2b80922297296","source":{"kind":"arxiv","id":"2106.02054","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2106.02054","created_at":"2026-07-05T02:55:15Z"},{"alias_kind":"arxiv_version","alias_value":"2106.02054v1","created_at":"2026-07-05T02:55:15Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2106.02054","created_at":"2026-07-05T02:55:15Z"},{"alias_kind":"pith_short_12","alias_value":"3ZNHBJRTFY63","created_at":"2026-07-05T02:55:15Z"},{"alias_kind":"pith_short_16","alias_value":"3ZNHBJRTFY63BM4G","created_at":"2026-07-05T02:55:15Z"},{"alias_kind":"pith_short_8","alias_value":"3ZNHBJRT","created_at":"2026-07-05T02:55:15Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2021:3ZNHBJRTFY63BM4GLXC4W5KDLO","target":"record","payload":{"canonical_record":{"source":{"id":"2106.02054","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.GA","submitted_at":"2021-06-03T18:00:08Z","cross_cats_sorted":["astro-ph.SR"],"title_canon_sha256":"5dee63483b052dc12e5da2f8578c99fefbfb7fcbccf0ff833cbfffbd6264c004","abstract_canon_sha256":"b09f88488a022842a4d21f1d88d0619a456205baade6af74f3a67a531aee812c"},"schema_version":"1.0"},"canonical_sha256":"de5a70a6332e3db0b3865dc5cb75435b803108ffef4c13ef78e2b80922297296","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T02:55:15.790498Z","signature_b64":"pP33xA3z88m84Czv2DVg4o7HIWtR7U4Q4IbkyCrBMAoxNs8KlvBGUZpR8+KVbmV4Q6uxBbBhXKh6Zxz1IcwWDw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"de5a70a6332e3db0b3865dc5cb75435b803108ffef4c13ef78e2b80922297296","last_reissued_at":"2026-07-05T02:55:15.789825Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T02:55:15.789825Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2106.02054","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":"2026-07-05T02:55:15Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"Jsv+uxVj+4JveRViDxNPPiAK/KzFTfz6a09OdlPqq9lzccFnIjL0A1c7n011nxqqpG7Rlz3zZtLXcgwhJfJ3Ag==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-08T19:49:26.428562Z"},"content_sha256":"b629149ea3a3c7959a15352c6c89e36e9cf59606772d5fb1ed6c1e28804b43a0","schema_version":"1.0","event_id":"sha256:b629149ea3a3c7959a15352c6c89e36e9cf59606772d5fb1ed6c1e28804b43a0"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2021:3ZNHBJRTFY63BM4GLXC4W5KDLO","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"On the Nitrogen variation in ~2 Gyr old massive star clusters in the Large Magellanic Cloud","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.SR"],"primary_cat":"astro-ph.GA","authors_text":"C. Lardo, E. Dalessandro, I. Cabrera-Ziri, M. Rejkuba, M. Salaris, N. Bastian, N. Kacharov, S. Kamann, S. Larsen, S. Martocchia, W. Chantereau","submitted_at":"2021-06-03T18:00:08Z","abstract_excerpt":"We present ESO/VLT FORS2 low resolution spectroscopy of red giant branch stars in three massive, intermediate age ($\\sim 1.7-2.3$ Gyr) star clusters in the Large Magellanic Cloud. We measure CH and CN index bands at 4300A, and 3883A, as well as [C/Fe] and [N/Fe] abundance ratios for 24, 21 and 12 member stars of NGC 1978, NGC 1651, NGC 1783, respectively. We find a significant intrinsic spread in CN in NGC 1978 and NGC 1651, a signal of multiple stellar populations (MPs) within the clusters. On the contrary, we report a null CN spread in NGC 1783 within our measurement precision. For NGC 1978,"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2106.02054","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/2106.02054/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"},"verdict_id":null},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-07-05T02:55:15Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"cm5QQ89v9NfI51UWWGPnuuCOW8dGM/HIirzLNw+GgoK11WJdudM1OAhxGJ3HUXQh0eJvpa83tpJgeyavjKMGBw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-08T19:49:26.429053Z"},"content_sha256":"40c4a2477693c2349ba447b6be9ae129f0b8f8dba1477ce7623af0f4d2aad5c2","schema_version":"1.0","event_id":"sha256:40c4a2477693c2349ba447b6be9ae129f0b8f8dba1477ce7623af0f4d2aad5c2"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/3ZNHBJRTFY63BM4GLXC4W5KDLO/bundle.json","state_url":"https://pith.science/pith/3ZNHBJRTFY63BM4GLXC4W5KDLO/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/3ZNHBJRTFY63BM4GLXC4W5KDLO/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":"2026-08-08T19:49:26Z","links":{"resolver":"https://pith.science/pith/3ZNHBJRTFY63BM4GLXC4W5KDLO","bundle":"https://pith.science/pith/3ZNHBJRTFY63BM4GLXC4W5KDLO/bundle.json","state":"https://pith.science/pith/3ZNHBJRTFY63BM4GLXC4W5KDLO/state.json","well_known_bundle":"https://pith.science/.well-known/pith/3ZNHBJRTFY63BM4GLXC4W5KDLO/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2021:3ZNHBJRTFY63BM4GLXC4W5KDLO","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":"b09f88488a022842a4d21f1d88d0619a456205baade6af74f3a67a531aee812c","cross_cats_sorted":["astro-ph.SR"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.GA","submitted_at":"2021-06-03T18:00:08Z","title_canon_sha256":"5dee63483b052dc12e5da2f8578c99fefbfb7fcbccf0ff833cbfffbd6264c004"},"schema_version":"1.0","source":{"id":"2106.02054","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2106.02054","created_at":"2026-07-05T02:55:15Z"},{"alias_kind":"arxiv_version","alias_value":"2106.02054v1","created_at":"2026-07-05T02:55:15Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2106.02054","created_at":"2026-07-05T02:55:15Z"},{"alias_kind":"pith_short_12","alias_value":"3ZNHBJRTFY63","created_at":"2026-07-05T02:55:15Z"},{"alias_kind":"pith_short_16","alias_value":"3ZNHBJRTFY63BM4G","created_at":"2026-07-05T02:55:15Z"},{"alias_kind":"pith_short_8","alias_value":"3ZNHBJRT","created_at":"2026-07-05T02:55:15Z"}],"graph_snapshots":[{"event_id":"sha256:40c4a2477693c2349ba447b6be9ae129f0b8f8dba1477ce7623af0f4d2aad5c2","target":"graph","created_at":"2026-07-05T02:55:15Z","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"},"integrity":{"available":true,"clean":true,"detectors_run":[],"endpoint":"/pith/2106.02054/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"We present ESO/VLT FORS2 low resolution spectroscopy of red giant branch stars in three massive, intermediate age ($\\sim 1.7-2.3$ Gyr) star clusters in the Large Magellanic Cloud. We measure CH and CN index bands at 4300A, and 3883A, as well as [C/Fe] and [N/Fe] abundance ratios for 24, 21 and 12 member stars of NGC 1978, NGC 1651, NGC 1783, respectively. We find a significant intrinsic spread in CN in NGC 1978 and NGC 1651, a signal of multiple stellar populations (MPs) within the clusters. On the contrary, we report a null CN spread in NGC 1783 within our measurement precision. For NGC 1978,","authors_text":"C. Lardo, E. Dalessandro, I. Cabrera-Ziri, M. Rejkuba, M. Salaris, N. Bastian, N. Kacharov, S. Kamann, S. Larsen, S. Martocchia, W. Chantereau","cross_cats":["astro-ph.SR"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.GA","submitted_at":"2021-06-03T18:00:08Z","title":"On the Nitrogen variation in ~2 Gyr old massive star clusters in the Large Magellanic Cloud"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2106.02054","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:b629149ea3a3c7959a15352c6c89e36e9cf59606772d5fb1ed6c1e28804b43a0","target":"record","created_at":"2026-07-05T02:55:15Z","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":"b09f88488a022842a4d21f1d88d0619a456205baade6af74f3a67a531aee812c","cross_cats_sorted":["astro-ph.SR"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.GA","submitted_at":"2021-06-03T18:00:08Z","title_canon_sha256":"5dee63483b052dc12e5da2f8578c99fefbfb7fcbccf0ff833cbfffbd6264c004"},"schema_version":"1.0","source":{"id":"2106.02054","kind":"arxiv","version":1}},"canonical_sha256":"de5a70a6332e3db0b3865dc5cb75435b803108ffef4c13ef78e2b80922297296","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"de5a70a6332e3db0b3865dc5cb75435b803108ffef4c13ef78e2b80922297296","first_computed_at":"2026-07-05T02:55:15.789825Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T02:55:15.789825Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"pP33xA3z88m84Czv2DVg4o7HIWtR7U4Q4IbkyCrBMAoxNs8KlvBGUZpR8+KVbmV4Q6uxBbBhXKh6Zxz1IcwWDw==","signature_status":"signed_v1","signed_at":"2026-07-05T02:55:15.790498Z","signed_message":"canonical_sha256_bytes"},"source_id":"2106.02054","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:b629149ea3a3c7959a15352c6c89e36e9cf59606772d5fb1ed6c1e28804b43a0","sha256:40c4a2477693c2349ba447b6be9ae129f0b8f8dba1477ce7623af0f4d2aad5c2"],"state_sha256":"bec05ac87be7b9416e3715fe35b8a1d37c9c18a241e32e5943936fc6ce927bd8"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"trG/nv0cejvl4f6OG2D8EC6CZSluG2wAmV1hePAuQY50bSnnBFk5y45UsdHg1hPVO9dlwq85GPoq9XSK+0U+Cg==","signed_message":"bundle_sha256_bytes","signed_at":"2026-08-08T19:49:26.432512Z","bundle_sha256":"85cc79c1d72cdc21d2518327b56b6aaaa87fa72131f685a87d04b9e6214d1a54"}}