{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2012:DM6QTZUJ46QVLQULJH7KEIZC3K","short_pith_number":"pith:DM6QTZUJ","canonical_record":{"source":{"id":"1210.1781","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.GA","submitted_at":"2012-10-05T15:11:20Z","cross_cats_sorted":["astro-ph.SR"],"title_canon_sha256":"c2667790e1e77ef137196c0dff7317701920b01fe02c06dcab5f4c2e3d94a758","abstract_canon_sha256":"744d6166c0c62d61e5be49631df769e85f1de3aa831356ba780fdd98fafffcfb"},"schema_version":"1.0"},"canonical_sha256":"1b3d09e689e7a155c28b49fea22322dabacdfa14409629bd0e713f66a8b26048","source":{"kind":"arxiv","id":"1210.1781","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1210.1781","created_at":"2026-05-18T03:43:53Z"},{"alias_kind":"arxiv_version","alias_value":"1210.1781v1","created_at":"2026-05-18T03:43:53Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1210.1781","created_at":"2026-05-18T03:43:53Z"},{"alias_kind":"pith_short_12","alias_value":"DM6QTZUJ46QV","created_at":"2026-05-18T12:27:04Z"},{"alias_kind":"pith_short_16","alias_value":"DM6QTZUJ46QVLQUL","created_at":"2026-05-18T12:27:04Z"},{"alias_kind":"pith_short_8","alias_value":"DM6QTZUJ","created_at":"2026-05-18T12:27:04Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2012:DM6QTZUJ46QVLQULJH7KEIZC3K","target":"record","payload":{"canonical_record":{"source":{"id":"1210.1781","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.GA","submitted_at":"2012-10-05T15:11:20Z","cross_cats_sorted":["astro-ph.SR"],"title_canon_sha256":"c2667790e1e77ef137196c0dff7317701920b01fe02c06dcab5f4c2e3d94a758","abstract_canon_sha256":"744d6166c0c62d61e5be49631df769e85f1de3aa831356ba780fdd98fafffcfb"},"schema_version":"1.0"},"canonical_sha256":"1b3d09e689e7a155c28b49fea22322dabacdfa14409629bd0e713f66a8b26048","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T03:43:53.321412Z","signature_b64":"p18KIbuTuF05UhbbUAVVOwOZ0Ns/HVCZ6SwYyHxpvJp4NfWTn9A4PJmlo0+tdwCxIRN5naT6HXB2MX+EM4K7Cw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"1b3d09e689e7a155c28b49fea22322dabacdfa14409629bd0e713f66a8b26048","last_reissued_at":"2026-05-18T03:43:53.320666Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T03:43:53.320666Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1210.1781","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":"2026-05-18T03:43:53Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"1jLP8fhsL04N7d2Ne+x4OJMlyxzDHOWYdSqdumr3erc//0afhmWGB6+xFiTZEZ0Ep9cd5f37ZfaTBwGpjVx1Cw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-30T15:08:22.249713Z"},"content_sha256":"29fd34967141daf684b78ec98c2b679ed6885b0a49cc8bcf3a420455a28ce266","schema_version":"1.0","event_id":"sha256:29fd34967141daf684b78ec98c2b679ed6885b0a49cc8bcf3a420455a28ce266"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2012:DM6QTZUJ46QVLQULJH7KEIZC3K","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Discovery and spectroscopic study of the massive Galactic cluster Mercer 81","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.SR"],"primary_cat":"astro-ph.GA","authors_text":"Ben Davies, Diego de la Fuente, Donald F. Figer, Francisco Najarro","submitted_at":"2012-10-05T15:11:20Z","abstract_excerpt":"During the last decade, hundreds of young massive cluster candidates have been detected in the disk of the Milky Way. We investigate one of these candidates, Mercer 81, which was discovered through a systematic search for stellar overdensities, with follow-up NICMOS/HST infrared narrow-band photometry to find emission-line stars and confirm it as a massive cluster. Surprisingly, the brightest stars turned out to be a chance alignment of foreground stars, while a real massive cluster was found among some fainter stars in the field. From a first spectroscopic study of four emission-line stars (I"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1210.1781","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":"2026-05-18T03:43:53Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"Pk1rK0ho6sKW8xL/d/VWsvcdBWu/LPTURzL51Ke9jyqLM9ODPQDbZNU7PtkCg4udHO/xf64G5KeM+uv8vf/tCQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-30T15:08:22.250062Z"},"content_sha256":"45b3c1b4daf8e66ea7044a846a3261fe723cb80cd586ccb77e9b88f57daa4f7a","schema_version":"1.0","event_id":"sha256:45b3c1b4daf8e66ea7044a846a3261fe723cb80cd586ccb77e9b88f57daa4f7a"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/DM6QTZUJ46QVLQULJH7KEIZC3K/bundle.json","state_url":"https://pith.science/pith/DM6QTZUJ46QVLQULJH7KEIZC3K/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/DM6QTZUJ46QVLQULJH7KEIZC3K/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":"2026-05-30T15:08:22Z","links":{"resolver":"https://pith.science/pith/DM6QTZUJ46QVLQULJH7KEIZC3K","bundle":"https://pith.science/pith/DM6QTZUJ46QVLQULJH7KEIZC3K/bundle.json","state":"https://pith.science/pith/DM6QTZUJ46QVLQULJH7KEIZC3K/state.json","well_known_bundle":"https://pith.science/.well-known/pith/DM6QTZUJ46QVLQULJH7KEIZC3K/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2012:DM6QTZUJ46QVLQULJH7KEIZC3K","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":"744d6166c0c62d61e5be49631df769e85f1de3aa831356ba780fdd98fafffcfb","cross_cats_sorted":["astro-ph.SR"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.GA","submitted_at":"2012-10-05T15:11:20Z","title_canon_sha256":"c2667790e1e77ef137196c0dff7317701920b01fe02c06dcab5f4c2e3d94a758"},"schema_version":"1.0","source":{"id":"1210.1781","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1210.1781","created_at":"2026-05-18T03:43:53Z"},{"alias_kind":"arxiv_version","alias_value":"1210.1781v1","created_at":"2026-05-18T03:43:53Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1210.1781","created_at":"2026-05-18T03:43:53Z"},{"alias_kind":"pith_short_12","alias_value":"DM6QTZUJ46QV","created_at":"2026-05-18T12:27:04Z"},{"alias_kind":"pith_short_16","alias_value":"DM6QTZUJ46QVLQUL","created_at":"2026-05-18T12:27:04Z"},{"alias_kind":"pith_short_8","alias_value":"DM6QTZUJ","created_at":"2026-05-18T12:27:04Z"}],"graph_snapshots":[{"event_id":"sha256:45b3c1b4daf8e66ea7044a846a3261fe723cb80cd586ccb77e9b88f57daa4f7a","target":"graph","created_at":"2026-05-18T03:43:53Z","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":"During the last decade, hundreds of young massive cluster candidates have been detected in the disk of the Milky Way. We investigate one of these candidates, Mercer 81, which was discovered through a systematic search for stellar overdensities, with follow-up NICMOS/HST infrared narrow-band photometry to find emission-line stars and confirm it as a massive cluster. Surprisingly, the brightest stars turned out to be a chance alignment of foreground stars, while a real massive cluster was found among some fainter stars in the field. From a first spectroscopic study of four emission-line stars (I","authors_text":"Ben Davies, Diego de la Fuente, Donald F. Figer, Francisco Najarro","cross_cats":["astro-ph.SR"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.GA","submitted_at":"2012-10-05T15:11:20Z","title":"Discovery and spectroscopic study of the massive Galactic cluster Mercer 81"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1210.1781","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":"sha256:29fd34967141daf684b78ec98c2b679ed6885b0a49cc8bcf3a420455a28ce266","target":"record","created_at":"2026-05-18T03:43:53Z","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":"744d6166c0c62d61e5be49631df769e85f1de3aa831356ba780fdd98fafffcfb","cross_cats_sorted":["astro-ph.SR"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.GA","submitted_at":"2012-10-05T15:11:20Z","title_canon_sha256":"c2667790e1e77ef137196c0dff7317701920b01fe02c06dcab5f4c2e3d94a758"},"schema_version":"1.0","source":{"id":"1210.1781","kind":"arxiv","version":1}},"canonical_sha256":"1b3d09e689e7a155c28b49fea22322dabacdfa14409629bd0e713f66a8b26048","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"1b3d09e689e7a155c28b49fea22322dabacdfa14409629bd0e713f66a8b26048","first_computed_at":"2026-05-18T03:43:53.320666Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T03:43:53.320666Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"p18KIbuTuF05UhbbUAVVOwOZ0Ns/HVCZ6SwYyHxpvJp4NfWTn9A4PJmlo0+tdwCxIRN5naT6HXB2MX+EM4K7Cw==","signature_status":"signed_v1","signed_at":"2026-05-18T03:43:53.321412Z","signed_message":"canonical_sha256_bytes"},"source_id":"1210.1781","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:29fd34967141daf684b78ec98c2b679ed6885b0a49cc8bcf3a420455a28ce266","sha256:45b3c1b4daf8e66ea7044a846a3261fe723cb80cd586ccb77e9b88f57daa4f7a"],"state_sha256":"ba1d7e4ea13cb248081a58fd9ce098c4fc910a7ce90f81fb38864046c7c9bb4c"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"aawJZAem/uzzuDGCokDuPjt8zLAJtz/L6GECtixLrrdQdnrJf9l8aP1FiAJ9Kzis8jv/KE0jd7UmxvJd5ZjQCg==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-30T15:08:22.252191Z","bundle_sha256":"368baaa79c4ef59430cb58f969e32b771040f1ba791df0e1639b9d0795578bf3"}}