{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2018:N2DDUJ2KAQONVN3XICCQ3NVJXX","short_pith_number":"pith:N2DDUJ2K","canonical_record":{"source":{"id":"1803.07562","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.SR","submitted_at":"2018-03-20T18:00:00Z","cross_cats_sorted":["astro-ph.HE"],"title_canon_sha256":"ad99be43729af7210f8ac3adbb8d4996924547f666572a3eb2a1e46314f1e0f6","abstract_canon_sha256":"2a7a1be91de92795d33c1404b3b4e691e023b30237c9c4a009c625c5b5568ac7"},"schema_version":"1.0"},"canonical_sha256":"6e863a274a041cdab77740850db6a9bde17713d6520dc12cac4a908e0a6b297a","source":{"kind":"arxiv","id":"1803.07562","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1803.07562","created_at":"2026-05-18T00:08:42Z"},{"alias_kind":"arxiv_version","alias_value":"1803.07562v2","created_at":"2026-05-18T00:08:42Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1803.07562","created_at":"2026-05-18T00:08:42Z"},{"alias_kind":"pith_short_12","alias_value":"N2DDUJ2KAQON","created_at":"2026-05-18T12:32:40Z"},{"alias_kind":"pith_short_16","alias_value":"N2DDUJ2KAQONVN3X","created_at":"2026-05-18T12:32:40Z"},{"alias_kind":"pith_short_8","alias_value":"N2DDUJ2K","created_at":"2026-05-18T12:32:40Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2018:N2DDUJ2KAQONVN3XICCQ3NVJXX","target":"record","payload":{"canonical_record":{"source":{"id":"1803.07562","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.SR","submitted_at":"2018-03-20T18:00:00Z","cross_cats_sorted":["astro-ph.HE"],"title_canon_sha256":"ad99be43729af7210f8ac3adbb8d4996924547f666572a3eb2a1e46314f1e0f6","abstract_canon_sha256":"2a7a1be91de92795d33c1404b3b4e691e023b30237c9c4a009c625c5b5568ac7"},"schema_version":"1.0"},"canonical_sha256":"6e863a274a041cdab77740850db6a9bde17713d6520dc12cac4a908e0a6b297a","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T00:08:42.925655Z","signature_b64":"kNgdqm1x8Ft7uayke6Na7h41zpkdyRt9Ng9kK9ojFzV0f/ogbpb1M+rryVnZrzKkEbCBkdCPvEjvaLq3qx6oCg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"6e863a274a041cdab77740850db6a9bde17713d6520dc12cac4a908e0a6b297a","last_reissued_at":"2026-05-18T00:08:42.925085Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T00:08:42.925085Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1803.07562","source_version":2,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T00:08:42Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"hoH+aWJHUTCYUVQlc1K5/bBYd+17xx35tQXVO49g2jrYtP60DorDqo8qcwjF93NqK+El70qd79OZjZG3kF5dDA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-28T07:19:06.885735Z"},"content_sha256":"260efd69557091a48b95c713539759c193a689e5b3d719921d1bef717b8cf75d","schema_version":"1.0","event_id":"sha256:260efd69557091a48b95c713539759c193a689e5b3d719921d1bef717b8cf75d"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2018:N2DDUJ2KAQONVN3XICCQ3NVJXX","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Tycho-B: an unlikely companion for SN 1572","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.HE"],"primary_cat":"astro-ph.SR","authors_text":"Knox S. Long, P. Frank Winkler, Tuan Do, W.E. Kerzendorf","submitted_at":"2018-03-20T18:00:00Z","abstract_excerpt":"If some or all Type Ia SNe arise from accretion onto a massive WD from a companion, then the companion will remain in some form after the SN explosion. Tycho-B is an unusual, relatively hot star along the line of sight to Tycho's SNR -- conclusively shown to be a Type Ia -- and has been suggested as such a companion. If the interior of Tycho's SNR contains unshocked Fe, and if Tycho-B is either within the SNR shell or in the background, then one might hope to see evidence of this in the UV spectrum. Such is the case for SN\\,1006, where spectra of the background Schweizer-Middleditch star, as w"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1803.07562","kind":"arxiv","version":2},"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":"2026-05-18T00:08:42Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"rQ3iNQk0jifRb+69qdFBDGQAG++7rsGJeEWh8FM5lUAS19aCZUHZYiMpNgsi8QxM2kDx0VheH4RwPKB7lMlmDQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-28T07:19:06.886340Z"},"content_sha256":"f1171fcc6b173e03d8f0bae8dc492293f96ae7cb69aa99cc5d9af6db475ae550","schema_version":"1.0","event_id":"sha256:f1171fcc6b173e03d8f0bae8dc492293f96ae7cb69aa99cc5d9af6db475ae550"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/N2DDUJ2KAQONVN3XICCQ3NVJXX/bundle.json","state_url":"https://pith.science/pith/N2DDUJ2KAQONVN3XICCQ3NVJXX/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/N2DDUJ2KAQONVN3XICCQ3NVJXX/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":"2026-05-28T07:19:06Z","links":{"resolver":"https://pith.science/pith/N2DDUJ2KAQONVN3XICCQ3NVJXX","bundle":"https://pith.science/pith/N2DDUJ2KAQONVN3XICCQ3NVJXX/bundle.json","state":"https://pith.science/pith/N2DDUJ2KAQONVN3XICCQ3NVJXX/state.json","well_known_bundle":"https://pith.science/.well-known/pith/N2DDUJ2KAQONVN3XICCQ3NVJXX/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2018:N2DDUJ2KAQONVN3XICCQ3NVJXX","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":"2a7a1be91de92795d33c1404b3b4e691e023b30237c9c4a009c625c5b5568ac7","cross_cats_sorted":["astro-ph.HE"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.SR","submitted_at":"2018-03-20T18:00:00Z","title_canon_sha256":"ad99be43729af7210f8ac3adbb8d4996924547f666572a3eb2a1e46314f1e0f6"},"schema_version":"1.0","source":{"id":"1803.07562","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1803.07562","created_at":"2026-05-18T00:08:42Z"},{"alias_kind":"arxiv_version","alias_value":"1803.07562v2","created_at":"2026-05-18T00:08:42Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1803.07562","created_at":"2026-05-18T00:08:42Z"},{"alias_kind":"pith_short_12","alias_value":"N2DDUJ2KAQON","created_at":"2026-05-18T12:32:40Z"},{"alias_kind":"pith_short_16","alias_value":"N2DDUJ2KAQONVN3X","created_at":"2026-05-18T12:32:40Z"},{"alias_kind":"pith_short_8","alias_value":"N2DDUJ2K","created_at":"2026-05-18T12:32:40Z"}],"graph_snapshots":[{"event_id":"sha256:f1171fcc6b173e03d8f0bae8dc492293f96ae7cb69aa99cc5d9af6db475ae550","target":"graph","created_at":"2026-05-18T00:08:42Z","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":"If some or all Type Ia SNe arise from accretion onto a massive WD from a companion, then the companion will remain in some form after the SN explosion. Tycho-B is an unusual, relatively hot star along the line of sight to Tycho's SNR -- conclusively shown to be a Type Ia -- and has been suggested as such a companion. If the interior of Tycho's SNR contains unshocked Fe, and if Tycho-B is either within the SNR shell or in the background, then one might hope to see evidence of this in the UV spectrum. Such is the case for SN\\,1006, where spectra of the background Schweizer-Middleditch star, as w","authors_text":"Knox S. Long, P. Frank Winkler, Tuan Do, W.E. Kerzendorf","cross_cats":["astro-ph.HE"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.SR","submitted_at":"2018-03-20T18:00:00Z","title":"Tycho-B: an unlikely companion for SN 1572"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1803.07562","kind":"arxiv","version":2},"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":"sha256:260efd69557091a48b95c713539759c193a689e5b3d719921d1bef717b8cf75d","target":"record","created_at":"2026-05-18T00:08:42Z","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":"2a7a1be91de92795d33c1404b3b4e691e023b30237c9c4a009c625c5b5568ac7","cross_cats_sorted":["astro-ph.HE"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.SR","submitted_at":"2018-03-20T18:00:00Z","title_canon_sha256":"ad99be43729af7210f8ac3adbb8d4996924547f666572a3eb2a1e46314f1e0f6"},"schema_version":"1.0","source":{"id":"1803.07562","kind":"arxiv","version":2}},"canonical_sha256":"6e863a274a041cdab77740850db6a9bde17713d6520dc12cac4a908e0a6b297a","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"6e863a274a041cdab77740850db6a9bde17713d6520dc12cac4a908e0a6b297a","first_computed_at":"2026-05-18T00:08:42.925085Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T00:08:42.925085Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"kNgdqm1x8Ft7uayke6Na7h41zpkdyRt9Ng9kK9ojFzV0f/ogbpb1M+rryVnZrzKkEbCBkdCPvEjvaLq3qx6oCg==","signature_status":"signed_v1","signed_at":"2026-05-18T00:08:42.925655Z","signed_message":"canonical_sha256_bytes"},"source_id":"1803.07562","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:260efd69557091a48b95c713539759c193a689e5b3d719921d1bef717b8cf75d","sha256:f1171fcc6b173e03d8f0bae8dc492293f96ae7cb69aa99cc5d9af6db475ae550"],"state_sha256":"be00de127a50fc425401f21ec4e14671a1fd8bf1d13ac29d4c7ed132c7df5732"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"Y9gUa7zfmu/7TfWySfaVUIQbKJu3WzqEiCnUFS2PAW3WGBDptMTYSDIXhpT2g9RovWaZZHIgG1PEcxpx+ad1CA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-28T07:19:06.889304Z","bundle_sha256":"02bc7942b11e4401caad6c032c73bfa955ddd5b374ec249b4bf3b3a96b520e5e"}}