{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2012:PWRPKUVDHZY6FSKUWTKZGEPFSW","short_pith_number":"pith:PWRPKUVD","canonical_record":{"source":{"id":"1204.4643","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2012-04-20T14:18:37Z","cross_cats_sorted":[],"title_canon_sha256":"7d564bc5107b2c95218185dc591a68bc7f12b566b17ee6a19fde1c4f505748de","abstract_canon_sha256":"858739d2ec180e52273765d84cd1b358aa23c64b29169a0e46cb8213fa263c7e"},"schema_version":"1.0"},"canonical_sha256":"7da2f552a33e71e2c954b4d59311e5959ecd44816486fb6c970d16dddb4848b4","source":{"kind":"arxiv","id":"1204.4643","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1204.4643","created_at":"2026-05-18T01:57:48Z"},{"alias_kind":"arxiv_version","alias_value":"1204.4643v1","created_at":"2026-05-18T01:57:48Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1204.4643","created_at":"2026-05-18T01:57:48Z"},{"alias_kind":"pith_short_12","alias_value":"PWRPKUVDHZY6","created_at":"2026-05-18T12:27:18Z"},{"alias_kind":"pith_short_16","alias_value":"PWRPKUVDHZY6FSKU","created_at":"2026-05-18T12:27:18Z"},{"alias_kind":"pith_short_8","alias_value":"PWRPKUVD","created_at":"2026-05-18T12:27:18Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2012:PWRPKUVDHZY6FSKUWTKZGEPFSW","target":"record","payload":{"canonical_record":{"source":{"id":"1204.4643","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2012-04-20T14:18:37Z","cross_cats_sorted":[],"title_canon_sha256":"7d564bc5107b2c95218185dc591a68bc7f12b566b17ee6a19fde1c4f505748de","abstract_canon_sha256":"858739d2ec180e52273765d84cd1b358aa23c64b29169a0e46cb8213fa263c7e"},"schema_version":"1.0"},"canonical_sha256":"7da2f552a33e71e2c954b4d59311e5959ecd44816486fb6c970d16dddb4848b4","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T01:57:48.103512Z","signature_b64":"k2+i9itGtCc9CDCONKOjuqnXSUEqVfJmTocFnVkw9gYDDXRNNLgwKY0JF4s1+D+oo4y0qFpDhsJIkuwKxHXcBg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"7da2f552a33e71e2c954b4d59311e5959ecd44816486fb6c970d16dddb4848b4","last_reissued_at":"2026-05-18T01:57:48.102967Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T01:57:48.102967Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1204.4643","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":"2026-05-18T01:57:48Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"W7oCcTtXrYRyEhjzZIVq1pobpGYNnN5zshzI9VT63KEBwuDR9Wa6+izV+Y2tCFs8Yk8n/bAQbYN0ad5BSbOKAA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-26T08:44:10.470291Z"},"content_sha256":"ccf67657f7b645b0ccc9b916190452c8efead0a28bb84c01615f53388097c94f","schema_version":"1.0","event_id":"sha256:ccf67657f7b645b0ccc9b916190452c8efead0a28bb84c01615f53388097c94f"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2012:PWRPKUVDHZY6FSKUWTKZGEPFSW","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"VLBI for Gravity Probe B. II. Monitoring of the Structure of the Reference Sources 3C 454.3, B2250+194, and B2252+172","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.IM","authors_text":"D. E. Lebach, I. I. Shapiro, J. I. Lederman, M. F. Bietenholz, M. I. Ratner, N. Bartel, P. Luca, R. R. Ransom","submitted_at":"2012-04-20T14:18:37Z","abstract_excerpt":"We used 8.4 GHz VLBI images obtained at up to 35 epochs between 1997 and 2005 to examine the radio structures of the main reference source, 3C 454.3, and two secondary reference sources, B2250+194 and B2252+172, for the guide star for the NASA/Stanford relativity mission Gravity Probe B (GP-B). For one epoch in 2004 May, we also obtained images at 5.0 and 15.4 GHz. The 35 8.4 GHz images for quasar 3C 454.3 confirm a complex, evolving, core-jet structure. We identified at each epoch a component, C1, near the easternmost edge of the core region. Simulations of the core region showed that C1 is l"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1204.4643","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":"2026-05-18T01:57:48Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"aJ+bNUoFn4ByMrJWeEsJK0H51JmVA2JeY1GMGjjxvlQXtpiLxKN8pl/FYsvkSoCsUdFaD3eWTC0KDgm1F2T4Aw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-26T08:44:10.470984Z"},"content_sha256":"54dcd5ae27c3057e016b8862663bebc3a27752cf0d6c8eceaac1acccff4739cf","schema_version":"1.0","event_id":"sha256:54dcd5ae27c3057e016b8862663bebc3a27752cf0d6c8eceaac1acccff4739cf"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/PWRPKUVDHZY6FSKUWTKZGEPFSW/bundle.json","state_url":"https://pith.science/pith/PWRPKUVDHZY6FSKUWTKZGEPFSW/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/PWRPKUVDHZY6FSKUWTKZGEPFSW/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":"2026-05-26T08:44:10Z","links":{"resolver":"https://pith.science/pith/PWRPKUVDHZY6FSKUWTKZGEPFSW","bundle":"https://pith.science/pith/PWRPKUVDHZY6FSKUWTKZGEPFSW/bundle.json","state":"https://pith.science/pith/PWRPKUVDHZY6FSKUWTKZGEPFSW/state.json","well_known_bundle":"https://pith.science/.well-known/pith/PWRPKUVDHZY6FSKUWTKZGEPFSW/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2012:PWRPKUVDHZY6FSKUWTKZGEPFSW","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":"858739d2ec180e52273765d84cd1b358aa23c64b29169a0e46cb8213fa263c7e","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2012-04-20T14:18:37Z","title_canon_sha256":"7d564bc5107b2c95218185dc591a68bc7f12b566b17ee6a19fde1c4f505748de"},"schema_version":"1.0","source":{"id":"1204.4643","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1204.4643","created_at":"2026-05-18T01:57:48Z"},{"alias_kind":"arxiv_version","alias_value":"1204.4643v1","created_at":"2026-05-18T01:57:48Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1204.4643","created_at":"2026-05-18T01:57:48Z"},{"alias_kind":"pith_short_12","alias_value":"PWRPKUVDHZY6","created_at":"2026-05-18T12:27:18Z"},{"alias_kind":"pith_short_16","alias_value":"PWRPKUVDHZY6FSKU","created_at":"2026-05-18T12:27:18Z"},{"alias_kind":"pith_short_8","alias_value":"PWRPKUVD","created_at":"2026-05-18T12:27:18Z"}],"graph_snapshots":[{"event_id":"sha256:54dcd5ae27c3057e016b8862663bebc3a27752cf0d6c8eceaac1acccff4739cf","target":"graph","created_at":"2026-05-18T01:57:48Z","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 used 8.4 GHz VLBI images obtained at up to 35 epochs between 1997 and 2005 to examine the radio structures of the main reference source, 3C 454.3, and two secondary reference sources, B2250+194 and B2252+172, for the guide star for the NASA/Stanford relativity mission Gravity Probe B (GP-B). For one epoch in 2004 May, we also obtained images at 5.0 and 15.4 GHz. The 35 8.4 GHz images for quasar 3C 454.3 confirm a complex, evolving, core-jet structure. We identified at each epoch a component, C1, near the easternmost edge of the core region. Simulations of the core region showed that C1 is l","authors_text":"D. E. Lebach, I. I. Shapiro, J. I. Lederman, M. F. Bietenholz, M. I. Ratner, N. Bartel, P. Luca, R. R. Ransom","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2012-04-20T14:18:37Z","title":"VLBI for Gravity Probe B. II. Monitoring of the Structure of the Reference Sources 3C 454.3, B2250+194, and B2252+172"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1204.4643","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:ccf67657f7b645b0ccc9b916190452c8efead0a28bb84c01615f53388097c94f","target":"record","created_at":"2026-05-18T01:57:48Z","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":"858739d2ec180e52273765d84cd1b358aa23c64b29169a0e46cb8213fa263c7e","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2012-04-20T14:18:37Z","title_canon_sha256":"7d564bc5107b2c95218185dc591a68bc7f12b566b17ee6a19fde1c4f505748de"},"schema_version":"1.0","source":{"id":"1204.4643","kind":"arxiv","version":1}},"canonical_sha256":"7da2f552a33e71e2c954b4d59311e5959ecd44816486fb6c970d16dddb4848b4","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"7da2f552a33e71e2c954b4d59311e5959ecd44816486fb6c970d16dddb4848b4","first_computed_at":"2026-05-18T01:57:48.102967Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T01:57:48.102967Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"k2+i9itGtCc9CDCONKOjuqnXSUEqVfJmTocFnVkw9gYDDXRNNLgwKY0JF4s1+D+oo4y0qFpDhsJIkuwKxHXcBg==","signature_status":"signed_v1","signed_at":"2026-05-18T01:57:48.103512Z","signed_message":"canonical_sha256_bytes"},"source_id":"1204.4643","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:ccf67657f7b645b0ccc9b916190452c8efead0a28bb84c01615f53388097c94f","sha256:54dcd5ae27c3057e016b8862663bebc3a27752cf0d6c8eceaac1acccff4739cf"],"state_sha256":"84f2bbc81f1b815e443cdd248677675214b4b2f0a17b369b6c988abc161b12aa"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"FqN5owSLGD/6pZwv6ID5m58hyCZVRoTbgTZV71u5K/p9Cqj5ekE0x02Di7lnm6On5fKHOZZAfUHlL3ICJJg1Cw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-26T08:44:10.473534Z","bundle_sha256":"7f6945b6338b2384b9432b4da0313a31dd8fba756e56ba44d6bc3a4eecf32aa5"}}