{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2017:D3RZKRBLWFNB2KXLVAQDUU7JHQ","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":"40041ea26794a3f21a8a89248c1aca3ce3a903c5c73d9c2efb9a4ffade1e4891","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.HE","submitted_at":"2017-09-07T23:52:20Z","title_canon_sha256":"9b5edfaa4da7578c9b43dc071b5a2bb369765c463e03ba21cfce184d4a66b90d"},"schema_version":"1.0","source":{"id":"1709.02487","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1709.02487","created_at":"2026-05-18T00:28:52Z"},{"alias_kind":"arxiv_version","alias_value":"1709.02487v1","created_at":"2026-05-18T00:28:52Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1709.02487","created_at":"2026-05-18T00:28:52Z"},{"alias_kind":"pith_short_12","alias_value":"D3RZKRBLWFNB","created_at":"2026-05-18T12:31:10Z"},{"alias_kind":"pith_short_16","alias_value":"D3RZKRBLWFNB2KXL","created_at":"2026-05-18T12:31:10Z"},{"alias_kind":"pith_short_8","alias_value":"D3RZKRBL","created_at":"2026-05-18T12:31:10Z"}],"graph_snapshots":[{"event_id":"sha256:aeca11bc7b01dd0e7000586a70c91f6854e7f4f26c642486d0caad5ee593a27f","target":"graph","created_at":"2026-05-18T00:28:52Z","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 present 888 visual-wavelength spectra of 122 nearby type II supernovae (SNe II) obtained between 1986 and 2009, and ranging between 3 and 363 days post explosion. In this first paper, we outline our observations and data reduction techniques, together with a characterization based on the spectral diversity of SNe~II. A statistical analysis of the spectral matching technique is discussed as an alternative to non-detection constraints for estimating SN explosion epochs. The time evolution of spectral lines is presented and analysed in terms of how this differs for SNe of different photometric","authors_text":"Alessandro Pizzella, Barry F. Madore, Carlos Contreras, Claudia P. Guti\\'errez, Enrico Cappellaro, Eric Y. Hsiao, Gast\\'on Folatelli, Jose Luis Prieto, Jos\\'e Maza, Joseph P. Anderson, Kevin Krisciunas, Lluis Galbany, Luc Dessart, Luis Gonz\\'alez, Maria T. Ruiz, Mario Hamuy, Mark M. Phillips, Massimo Della Valle, Massimo Turatto, Mauricio Navarrete, Maximilian D. Stritzinger, Nicholas B. Suntzeff, Nidia Morrell, R. Chris Smith, Santiago Gonz\\'alez-Gaitan, Wendy L. Freedman","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.HE","submitted_at":"2017-09-07T23:52:20Z","title":"Type II supernova spectral diversity I: Observations, sample characterization and spectral line evolution"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1709.02487","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":"sha256:42647cd1e43eea12566a27781d6902cac0dc450f5c416a9db6ab295a5b6cfb9f","target":"record","created_at":"2026-05-18T00:28:52Z","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":"40041ea26794a3f21a8a89248c1aca3ce3a903c5c73d9c2efb9a4ffade1e4891","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.HE","submitted_at":"2017-09-07T23:52:20Z","title_canon_sha256":"9b5edfaa4da7578c9b43dc071b5a2bb369765c463e03ba21cfce184d4a66b90d"},"schema_version":"1.0","source":{"id":"1709.02487","kind":"arxiv","version":1}},"canonical_sha256":"1ee395442bb15a1d2aeba8203a53e93c3d538954d085d85f7f56d9c16a4cd8b0","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"1ee395442bb15a1d2aeba8203a53e93c3d538954d085d85f7f56d9c16a4cd8b0","first_computed_at":"2026-05-18T00:28:52.790778Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T00:28:52.790778Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"ZWhq53R995wNyvnErb7VWffbvMxGSXmdSzCFWcFvNnltJJ0+D6tLdAjLz90VMbUFsW9BoUVDcTkc+MuWw2DvAg==","signature_status":"signed_v1","signed_at":"2026-05-18T00:28:52.791274Z","signed_message":"canonical_sha256_bytes"},"source_id":"1709.02487","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:42647cd1e43eea12566a27781d6902cac0dc450f5c416a9db6ab295a5b6cfb9f","sha256:aeca11bc7b01dd0e7000586a70c91f6854e7f4f26c642486d0caad5ee593a27f"],"state_sha256":"404637da72806edd60d4ddfa0a3e78faa96f7c5ed792bde798886a2b938bfd99"}