{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2015:ZK5LKDKAUSC5JULP3DWJQYJ5WG","short_pith_number":"pith:ZK5LKDKA","canonical_record":{"source":{"id":"1511.01896","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2015-11-05T21:00:01Z","cross_cats_sorted":[],"title_canon_sha256":"8c47550e7354e167cf0ff08fe8a0bfc14f2eaa9a610b79bff99b0f6ecadcb51c","abstract_canon_sha256":"6899a0d985c3197a954c20583560e3b7b81f6a93b9f4c77ab4e3ddb23d8dcb3a"},"schema_version":"1.0"},"canonical_sha256":"cabab50d40a485d4d16fd8ec98613db1be9e1d36f9ec311f7aa24789e6760d76","source":{"kind":"arxiv","id":"1511.01896","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1511.01896","created_at":"2026-05-18T01:21:52Z"},{"alias_kind":"arxiv_version","alias_value":"1511.01896v2","created_at":"2026-05-18T01:21:52Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1511.01896","created_at":"2026-05-18T01:21:52Z"},{"alias_kind":"pith_short_12","alias_value":"ZK5LKDKAUSC5","created_at":"2026-05-18T12:29:52Z"},{"alias_kind":"pith_short_16","alias_value":"ZK5LKDKAUSC5JULP","created_at":"2026-05-18T12:29:52Z"},{"alias_kind":"pith_short_8","alias_value":"ZK5LKDKA","created_at":"2026-05-18T12:29:52Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2015:ZK5LKDKAUSC5JULP3DWJQYJ5WG","target":"record","payload":{"canonical_record":{"source":{"id":"1511.01896","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2015-11-05T21:00:01Z","cross_cats_sorted":[],"title_canon_sha256":"8c47550e7354e167cf0ff08fe8a0bfc14f2eaa9a610b79bff99b0f6ecadcb51c","abstract_canon_sha256":"6899a0d985c3197a954c20583560e3b7b81f6a93b9f4c77ab4e3ddb23d8dcb3a"},"schema_version":"1.0"},"canonical_sha256":"cabab50d40a485d4d16fd8ec98613db1be9e1d36f9ec311f7aa24789e6760d76","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T01:21:52.025732Z","signature_b64":"A0s0TdOlvDkVKljrE6MLmhY3douCbLQgp3Xy9FiUJrNinCxUUrQoj8A5xc7KSW1Quc0um1btHXF9x6mLf1OMCA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"cabab50d40a485d4d16fd8ec98613db1be9e1d36f9ec311f7aa24789e6760d76","last_reissued_at":"2026-05-18T01:21:52.025255Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T01:21:52.025255Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1511.01896","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":"2026-05-18T01:21:52Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"8bb/WClCHGenGWQ8+3dL1b7h+XXglz7N3IgG8saKpm5UpCEjDSGb6L6fRl2as5LNTmB66+UQjkD3Lsh8/qqLBQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-01T15:15:29.109663Z"},"content_sha256":"17acc1a382a212db668b7bce6fb464e92453d45485ea0948c5c2251e70764ea6","schema_version":"1.0","event_id":"sha256:17acc1a382a212db668b7bce6fb464e92453d45485ea0948c5c2251e70764ea6"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2015:ZK5LKDKAUSC5JULP3DWJQYJ5WG","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Quasars can be used to verify the parallax zero-point of the Tycho-Gaia Astrometric Solution","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.IM","authors_text":"Daniel Michalik, Lennart Lindegren","submitted_at":"2015-11-05T21:00:01Z","abstract_excerpt":"Context. The Gaia project will determine positions, proper motions, and parallaxes for more than one billion stars in our Galaxy. It is known that Gaia's two telescopes are affected by a small but significant variation of the basic angle between them. Unless this variation is taken into account during data processing, e.g. using on-board metrology, it causes systematic errors in the astrometric parameters, in particular a shift of the parallax zero-point. Previously, we suggested an early reduction of Gaia data for the subset of Tycho-2 stars (Tycho-Gaia Astrometric Solution; TGAS).\n  Aims. We"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1511.01896","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":"2026-05-18T01:21:52Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"OEqwHYoUh/HUiRXzkTS17ZpC2EdPjvPwJIMdbfJoVTRPnOyeVaDjLqeTh7634oBZS0vB9Mx4pz+Jk6wc7B+BBw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-01T15:15:29.110007Z"},"content_sha256":"611b002fece64423647899271f74e064ca8574619fafd9b470ca1e7e05cf1b46","schema_version":"1.0","event_id":"sha256:611b002fece64423647899271f74e064ca8574619fafd9b470ca1e7e05cf1b46"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/ZK5LKDKAUSC5JULP3DWJQYJ5WG/bundle.json","state_url":"https://pith.science/pith/ZK5LKDKAUSC5JULP3DWJQYJ5WG/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/ZK5LKDKAUSC5JULP3DWJQYJ5WG/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":"2026-06-01T15:15:29Z","links":{"resolver":"https://pith.science/pith/ZK5LKDKAUSC5JULP3DWJQYJ5WG","bundle":"https://pith.science/pith/ZK5LKDKAUSC5JULP3DWJQYJ5WG/bundle.json","state":"https://pith.science/pith/ZK5LKDKAUSC5JULP3DWJQYJ5WG/state.json","well_known_bundle":"https://pith.science/.well-known/pith/ZK5LKDKAUSC5JULP3DWJQYJ5WG/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2015:ZK5LKDKAUSC5JULP3DWJQYJ5WG","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":"6899a0d985c3197a954c20583560e3b7b81f6a93b9f4c77ab4e3ddb23d8dcb3a","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2015-11-05T21:00:01Z","title_canon_sha256":"8c47550e7354e167cf0ff08fe8a0bfc14f2eaa9a610b79bff99b0f6ecadcb51c"},"schema_version":"1.0","source":{"id":"1511.01896","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1511.01896","created_at":"2026-05-18T01:21:52Z"},{"alias_kind":"arxiv_version","alias_value":"1511.01896v2","created_at":"2026-05-18T01:21:52Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1511.01896","created_at":"2026-05-18T01:21:52Z"},{"alias_kind":"pith_short_12","alias_value":"ZK5LKDKAUSC5","created_at":"2026-05-18T12:29:52Z"},{"alias_kind":"pith_short_16","alias_value":"ZK5LKDKAUSC5JULP","created_at":"2026-05-18T12:29:52Z"},{"alias_kind":"pith_short_8","alias_value":"ZK5LKDKA","created_at":"2026-05-18T12:29:52Z"}],"graph_snapshots":[{"event_id":"sha256:611b002fece64423647899271f74e064ca8574619fafd9b470ca1e7e05cf1b46","target":"graph","created_at":"2026-05-18T01:21:52Z","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":"Context. The Gaia project will determine positions, proper motions, and parallaxes for more than one billion stars in our Galaxy. It is known that Gaia's two telescopes are affected by a small but significant variation of the basic angle between them. Unless this variation is taken into account during data processing, e.g. using on-board metrology, it causes systematic errors in the astrometric parameters, in particular a shift of the parallax zero-point. Previously, we suggested an early reduction of Gaia data for the subset of Tycho-2 stars (Tycho-Gaia Astrometric Solution; TGAS).\n  Aims. We","authors_text":"Daniel Michalik, Lennart Lindegren","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2015-11-05T21:00:01Z","title":"Quasars can be used to verify the parallax zero-point of the Tycho-Gaia Astrometric Solution"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1511.01896","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":"sha256:17acc1a382a212db668b7bce6fb464e92453d45485ea0948c5c2251e70764ea6","target":"record","created_at":"2026-05-18T01:21:52Z","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":"6899a0d985c3197a954c20583560e3b7b81f6a93b9f4c77ab4e3ddb23d8dcb3a","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2015-11-05T21:00:01Z","title_canon_sha256":"8c47550e7354e167cf0ff08fe8a0bfc14f2eaa9a610b79bff99b0f6ecadcb51c"},"schema_version":"1.0","source":{"id":"1511.01896","kind":"arxiv","version":2}},"canonical_sha256":"cabab50d40a485d4d16fd8ec98613db1be9e1d36f9ec311f7aa24789e6760d76","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"cabab50d40a485d4d16fd8ec98613db1be9e1d36f9ec311f7aa24789e6760d76","first_computed_at":"2026-05-18T01:21:52.025255Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T01:21:52.025255Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"A0s0TdOlvDkVKljrE6MLmhY3douCbLQgp3Xy9FiUJrNinCxUUrQoj8A5xc7KSW1Quc0um1btHXF9x6mLf1OMCA==","signature_status":"signed_v1","signed_at":"2026-05-18T01:21:52.025732Z","signed_message":"canonical_sha256_bytes"},"source_id":"1511.01896","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:17acc1a382a212db668b7bce6fb464e92453d45485ea0948c5c2251e70764ea6","sha256:611b002fece64423647899271f74e064ca8574619fafd9b470ca1e7e05cf1b46"],"state_sha256":"cef1ceec357436d6acdbb9d6282d629d2faa17a30c030d74f84d358115ad891e"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"RjVx4cqu5+hIeIkZkPJiHiqSXOcHCLMlT/HdQUw3xboENNAabkCfprt6FGZkieSrUhdmzn+BOa9RODVd0shyDQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-01T15:15:29.111929Z","bundle_sha256":"c6d630565b3a69b63055125a2018aace4bccfe754f41d02332884b887cd25fca"}}