{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2015:VZ2P5PA2IVOGM2HJPTJK5XOTWW","short_pith_number":"pith:VZ2P5PA2","canonical_record":{"source":{"id":"1504.03299","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.SR","submitted_at":"2015-04-13T18:59:19Z","cross_cats_sorted":["astro-ph.GA"],"title_canon_sha256":"e48c2ff5ff663cc0101061814a2b5fd1f3deeac74a8725dd81d0835e2c7e48a8","abstract_canon_sha256":"0dc8a5f5dc02975ffa03043f6dec89505d93a372623b5a1706e1b00f63a2c02a"},"schema_version":"1.0"},"canonical_sha256":"ae74febc1a455c6668e97cd2aeddd3b5a1a8009967187b03a6afef5e6a989e50","source":{"kind":"arxiv","id":"1504.03299","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1504.03299","created_at":"2026-05-18T02:03:32Z"},{"alias_kind":"arxiv_version","alias_value":"1504.03299v1","created_at":"2026-05-18T02:03:32Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1504.03299","created_at":"2026-05-18T02:03:32Z"},{"alias_kind":"pith_short_12","alias_value":"VZ2P5PA2IVOG","created_at":"2026-05-18T12:29:47Z"},{"alias_kind":"pith_short_16","alias_value":"VZ2P5PA2IVOGM2HJ","created_at":"2026-05-18T12:29:47Z"},{"alias_kind":"pith_short_8","alias_value":"VZ2P5PA2","created_at":"2026-05-18T12:29:47Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2015:VZ2P5PA2IVOGM2HJPTJK5XOTWW","target":"record","payload":{"canonical_record":{"source":{"id":"1504.03299","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.SR","submitted_at":"2015-04-13T18:59:19Z","cross_cats_sorted":["astro-ph.GA"],"title_canon_sha256":"e48c2ff5ff663cc0101061814a2b5fd1f3deeac74a8725dd81d0835e2c7e48a8","abstract_canon_sha256":"0dc8a5f5dc02975ffa03043f6dec89505d93a372623b5a1706e1b00f63a2c02a"},"schema_version":"1.0"},"canonical_sha256":"ae74febc1a455c6668e97cd2aeddd3b5a1a8009967187b03a6afef5e6a989e50","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T02:03:32.877505Z","signature_b64":"45XhBEQ2Sj732bE1+WRheqppWOAjQzot79MTHncBpK8xJtIA18gdNMQo7evOyJLlcX1w4Qk/+ZEx+A14j96JDA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"ae74febc1a455c6668e97cd2aeddd3b5a1a8009967187b03a6afef5e6a989e50","last_reissued_at":"2026-05-18T02:03:32.876837Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T02:03:32.876837Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1504.03299","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":"2026-05-18T02:03:32Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"x0Remw8sM3XYHm/1p8eBPd2INa2j5dF0wwOCkguGnezrFMCa7PuAxoYG57+XZV7HjS7Nj2JR2miVx+Arshq+Aw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-10T01:14:15.895258Z"},"content_sha256":"22d808ae5c90202ca115456307a97ce9d3a8ec6b4a34ff4e1f0daba44eeead38","schema_version":"1.0","event_id":"sha256:22d808ae5c90202ca115456307a97ce9d3a8ec6b4a34ff4e1f0daba44eeead38"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2015:VZ2P5PA2IVOGM2HJPTJK5XOTWW","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"New Constraints on the Star Formation History of the Star Cluster NGC 1856","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.GA"],"primary_cat":"astro-ph.SR","authors_text":"(2) P. Univ. Catolica de Chile, (3) Univ. of Amsterdam), Matteo Correnti (1), Paul Goudfrooij (1), Selma E. de Mink (3) ((1) STScI, Thomas H. Puzia (2)","submitted_at":"2015-04-13T18:59:19Z","abstract_excerpt":"We use the Wide Field Camera 3 onboard the Hubble Space Telescope to obtain deep, high-resolution photometry of the young (age ~ 300 Myr) star cluster NGC1856 in the Large Magellanic Cloud. We compare the observed colour-magnitude diagram (CMD), after having applied a correction for differential reddening, with Monte Carlo simulations of simple stellar populations (SSPs) of various ages. We find that the main sequence turn-off (MSTO) region is wider than that derived from the simulation of a single SSP. Using constraints based on the distribution of stars in the MSTO region and the red clump, "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1504.03299","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":"2026-05-18T02:03:32Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"eQsGReMvIwaPVmiCU3tb6/MHDNgtHsuuj/KvvIO+9lh3yLKPel1lYxN2EdvLuQ+he+pTspcHjSWTW3g7tJdPBA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-10T01:14:15.895990Z"},"content_sha256":"e0ca3601825a7e2ad683875db5cd52ef65b14aec026aef0298fb8404087d4a44","schema_version":"1.0","event_id":"sha256:e0ca3601825a7e2ad683875db5cd52ef65b14aec026aef0298fb8404087d4a44"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/VZ2P5PA2IVOGM2HJPTJK5XOTWW/bundle.json","state_url":"https://pith.science/pith/VZ2P5PA2IVOGM2HJPTJK5XOTWW/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/VZ2P5PA2IVOGM2HJPTJK5XOTWW/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":"2026-06-10T01:14:15Z","links":{"resolver":"https://pith.science/pith/VZ2P5PA2IVOGM2HJPTJK5XOTWW","bundle":"https://pith.science/pith/VZ2P5PA2IVOGM2HJPTJK5XOTWW/bundle.json","state":"https://pith.science/pith/VZ2P5PA2IVOGM2HJPTJK5XOTWW/state.json","well_known_bundle":"https://pith.science/.well-known/pith/VZ2P5PA2IVOGM2HJPTJK5XOTWW/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2015:VZ2P5PA2IVOGM2HJPTJK5XOTWW","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":"0dc8a5f5dc02975ffa03043f6dec89505d93a372623b5a1706e1b00f63a2c02a","cross_cats_sorted":["astro-ph.GA"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.SR","submitted_at":"2015-04-13T18:59:19Z","title_canon_sha256":"e48c2ff5ff663cc0101061814a2b5fd1f3deeac74a8725dd81d0835e2c7e48a8"},"schema_version":"1.0","source":{"id":"1504.03299","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1504.03299","created_at":"2026-05-18T02:03:32Z"},{"alias_kind":"arxiv_version","alias_value":"1504.03299v1","created_at":"2026-05-18T02:03:32Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1504.03299","created_at":"2026-05-18T02:03:32Z"},{"alias_kind":"pith_short_12","alias_value":"VZ2P5PA2IVOG","created_at":"2026-05-18T12:29:47Z"},{"alias_kind":"pith_short_16","alias_value":"VZ2P5PA2IVOGM2HJ","created_at":"2026-05-18T12:29:47Z"},{"alias_kind":"pith_short_8","alias_value":"VZ2P5PA2","created_at":"2026-05-18T12:29:47Z"}],"graph_snapshots":[{"event_id":"sha256:e0ca3601825a7e2ad683875db5cd52ef65b14aec026aef0298fb8404087d4a44","target":"graph","created_at":"2026-05-18T02:03:32Z","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":"We use the Wide Field Camera 3 onboard the Hubble Space Telescope to obtain deep, high-resolution photometry of the young (age ~ 300 Myr) star cluster NGC1856 in the Large Magellanic Cloud. We compare the observed colour-magnitude diagram (CMD), after having applied a correction for differential reddening, with Monte Carlo simulations of simple stellar populations (SSPs) of various ages. We find that the main sequence turn-off (MSTO) region is wider than that derived from the simulation of a single SSP. Using constraints based on the distribution of stars in the MSTO region and the red clump, ","authors_text":"(2) P. Univ. Catolica de Chile, (3) Univ. of Amsterdam), Matteo Correnti (1), Paul Goudfrooij (1), Selma E. de Mink (3) ((1) STScI, Thomas H. Puzia (2)","cross_cats":["astro-ph.GA"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.SR","submitted_at":"2015-04-13T18:59:19Z","title":"New Constraints on the Star Formation History of the Star Cluster NGC 1856"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1504.03299","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":"sha256:22d808ae5c90202ca115456307a97ce9d3a8ec6b4a34ff4e1f0daba44eeead38","target":"record","created_at":"2026-05-18T02:03:32Z","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":"0dc8a5f5dc02975ffa03043f6dec89505d93a372623b5a1706e1b00f63a2c02a","cross_cats_sorted":["astro-ph.GA"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.SR","submitted_at":"2015-04-13T18:59:19Z","title_canon_sha256":"e48c2ff5ff663cc0101061814a2b5fd1f3deeac74a8725dd81d0835e2c7e48a8"},"schema_version":"1.0","source":{"id":"1504.03299","kind":"arxiv","version":1}},"canonical_sha256":"ae74febc1a455c6668e97cd2aeddd3b5a1a8009967187b03a6afef5e6a989e50","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"ae74febc1a455c6668e97cd2aeddd3b5a1a8009967187b03a6afef5e6a989e50","first_computed_at":"2026-05-18T02:03:32.876837Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T02:03:32.876837Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"45XhBEQ2Sj732bE1+WRheqppWOAjQzot79MTHncBpK8xJtIA18gdNMQo7evOyJLlcX1w4Qk/+ZEx+A14j96JDA==","signature_status":"signed_v1","signed_at":"2026-05-18T02:03:32.877505Z","signed_message":"canonical_sha256_bytes"},"source_id":"1504.03299","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:22d808ae5c90202ca115456307a97ce9d3a8ec6b4a34ff4e1f0daba44eeead38","sha256:e0ca3601825a7e2ad683875db5cd52ef65b14aec026aef0298fb8404087d4a44"],"state_sha256":"6a5abe270c4ff2d6cc5eca8ae760a902edf3a2a5f0720e81c86bc0265de9a5c1"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"vtKj+kxinLqCiyMDqQmmmnGFEzSH+lP6SF5MyMn0b7sbE95ydnUo+heCwbUancXf36xq/o5Watds+0fhUoSWDg==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-10T01:14:15.900036Z","bundle_sha256":"b65ad79be8aa231d5186e2b7d4c55afb5c264f0df6cec28a32d33ba1356547e7"}}