{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2008:ROXTGK3LDUZJD2WXAKDYQ7B6RX","short_pith_number":"pith:ROXTGK3L","canonical_record":{"source":{"id":"0811.2264","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph","submitted_at":"2008-11-14T04:32:20Z","cross_cats_sorted":[],"title_canon_sha256":"fa2b46b53656ee8b1723c0df2a452d598f1ac8f7e2d77b976cbd90cc1d2fd9f1","abstract_canon_sha256":"9a9f662ae17d2c539ab245246cea7619763c0de0ab2a352625410add9a1c71ba"},"schema_version":"1.0"},"canonical_sha256":"8baf332b6b1d3291ead70287887c3e8dd847e0298deaf7c17c549ca47628ca3d","source":{"kind":"arxiv","id":"0811.2264","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"0811.2264","created_at":"2026-05-18T02:35:13Z"},{"alias_kind":"arxiv_version","alias_value":"0811.2264v2","created_at":"2026-05-18T02:35:13Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.0811.2264","created_at":"2026-05-18T02:35:13Z"},{"alias_kind":"pith_short_12","alias_value":"ROXTGK3LDUZJ","created_at":"2026-05-18T12:25:58Z"},{"alias_kind":"pith_short_16","alias_value":"ROXTGK3LDUZJD2WX","created_at":"2026-05-18T12:25:58Z"},{"alias_kind":"pith_short_8","alias_value":"ROXTGK3L","created_at":"2026-05-18T12:25:58Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2008:ROXTGK3LDUZJD2WXAKDYQ7B6RX","target":"record","payload":{"canonical_record":{"source":{"id":"0811.2264","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph","submitted_at":"2008-11-14T04:32:20Z","cross_cats_sorted":[],"title_canon_sha256":"fa2b46b53656ee8b1723c0df2a452d598f1ac8f7e2d77b976cbd90cc1d2fd9f1","abstract_canon_sha256":"9a9f662ae17d2c539ab245246cea7619763c0de0ab2a352625410add9a1c71ba"},"schema_version":"1.0"},"canonical_sha256":"8baf332b6b1d3291ead70287887c3e8dd847e0298deaf7c17c549ca47628ca3d","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T02:35:13.896711Z","signature_b64":"FVt5A/8RfmjSCPD+NYJJu7VDlfFoo+WwfByl19k8E928dg0Rvxb1J4Ik50Q3rNCri1FQEmB7LXWzKX/Vh+q3AA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"8baf332b6b1d3291ead70287887c3e8dd847e0298deaf7c17c549ca47628ca3d","last_reissued_at":"2026-05-18T02:35:13.896294Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T02:35:13.896294Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"0811.2264","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":"2026-05-18T02:35:13Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"Or2ecjFpKFqyU52/O1YF9wjyKA4OmzLnzacsL0t0aDIO6iK+6FOuYdBXFb+WVebKf/9ghVe+EG3PRwExaV46CQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-22T14:17:34.097649Z"},"content_sha256":"8af6a54411f10fbe436f65240896727837503c34aa431a83eb6c0b84f3dec9a7","schema_version":"1.0","event_id":"sha256:8af6a54411f10fbe436f65240896727837503c34aa431a83eb6c0b84f3dec9a7"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2008:ROXTGK3LDUZJD2WXAKDYQ7B6RX","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Astrometry with the Keck-Interferometer: the ASTRA project and its science","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph","authors_text":"Andrea M. Ghez, Andrew Cooper, Ben Berkey, Bill Randolph, Brett Smith, Colette Tyau, Douglas Morrison, Drew Medeiros, Ed Wetherell, Eliot Quataert, James R. Graham, John Monnier, Jorg-Uwe Pott, Josh A. Eisner, Julien Woillez, Kellee Summers, Kevin Tsubota, Lynne Hillenbrand, Mark M. Colavita, Michael Hrynewych, Nevin Weinberg, Peter L. Wizinowich, Rachel L. Akeson, Rafael Millan-Gabet, Tatyana Panteleeva","submitted_at":"2008-11-14T04:32:20Z","abstract_excerpt":"The sensitivity and astrometry upgrade ASTRA of the Keck Interferometer is introduced. After a brief overview of the underlying interferometric principles, the technology and concepts of the upgrade are presented. The interferometric dual-field technology of ASTRA will provide the KI with the means to observe two objects simultaneously, and measure the distance between them with a precision eventually better than 100 uas. This astrometric functionality of ASTRA will add a unique observing tool to fields of astrophysical research as diverse as exo-planetary kinematics, binary astrometry, and th"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0811.2264","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":"2026-05-18T02:35:13Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"pZD6NCCE7wD7ZBmIJv3iIkFh3z5wzIcF+RwrPlktwu7zVYxxc8Uib6DM5vRKX3c7caegd6dOvB9o0V1Q22DDDw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-22T14:17:34.098394Z"},"content_sha256":"9160d4e664c588d3497b02e9b6854b8b24e687d5687066f23f744e3fc9e3aa08","schema_version":"1.0","event_id":"sha256:9160d4e664c588d3497b02e9b6854b8b24e687d5687066f23f744e3fc9e3aa08"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/ROXTGK3LDUZJD2WXAKDYQ7B6RX/bundle.json","state_url":"https://pith.science/pith/ROXTGK3LDUZJD2WXAKDYQ7B6RX/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/ROXTGK3LDUZJD2WXAKDYQ7B6RX/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":"2026-05-22T14:17:34Z","links":{"resolver":"https://pith.science/pith/ROXTGK3LDUZJD2WXAKDYQ7B6RX","bundle":"https://pith.science/pith/ROXTGK3LDUZJD2WXAKDYQ7B6RX/bundle.json","state":"https://pith.science/pith/ROXTGK3LDUZJD2WXAKDYQ7B6RX/state.json","well_known_bundle":"https://pith.science/.well-known/pith/ROXTGK3LDUZJD2WXAKDYQ7B6RX/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2008:ROXTGK3LDUZJD2WXAKDYQ7B6RX","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":"9a9f662ae17d2c539ab245246cea7619763c0de0ab2a352625410add9a1c71ba","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph","submitted_at":"2008-11-14T04:32:20Z","title_canon_sha256":"fa2b46b53656ee8b1723c0df2a452d598f1ac8f7e2d77b976cbd90cc1d2fd9f1"},"schema_version":"1.0","source":{"id":"0811.2264","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"0811.2264","created_at":"2026-05-18T02:35:13Z"},{"alias_kind":"arxiv_version","alias_value":"0811.2264v2","created_at":"2026-05-18T02:35:13Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.0811.2264","created_at":"2026-05-18T02:35:13Z"},{"alias_kind":"pith_short_12","alias_value":"ROXTGK3LDUZJ","created_at":"2026-05-18T12:25:58Z"},{"alias_kind":"pith_short_16","alias_value":"ROXTGK3LDUZJD2WX","created_at":"2026-05-18T12:25:58Z"},{"alias_kind":"pith_short_8","alias_value":"ROXTGK3L","created_at":"2026-05-18T12:25:58Z"}],"graph_snapshots":[{"event_id":"sha256:9160d4e664c588d3497b02e9b6854b8b24e687d5687066f23f744e3fc9e3aa08","target":"graph","created_at":"2026-05-18T02:35:13Z","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":"The sensitivity and astrometry upgrade ASTRA of the Keck Interferometer is introduced. After a brief overview of the underlying interferometric principles, the technology and concepts of the upgrade are presented. The interferometric dual-field technology of ASTRA will provide the KI with the means to observe two objects simultaneously, and measure the distance between them with a precision eventually better than 100 uas. This astrometric functionality of ASTRA will add a unique observing tool to fields of astrophysical research as diverse as exo-planetary kinematics, binary astrometry, and th","authors_text":"Andrea M. Ghez, Andrew Cooper, Ben Berkey, Bill Randolph, Brett Smith, Colette Tyau, Douglas Morrison, Drew Medeiros, Ed Wetherell, Eliot Quataert, James R. Graham, John Monnier, Jorg-Uwe Pott, Josh A. Eisner, Julien Woillez, Kellee Summers, Kevin Tsubota, Lynne Hillenbrand, Mark M. Colavita, Michael Hrynewych, Nevin Weinberg, Peter L. Wizinowich, Rachel L. Akeson, Rafael Millan-Gabet, Tatyana Panteleeva","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph","submitted_at":"2008-11-14T04:32:20Z","title":"Astrometry with the Keck-Interferometer: the ASTRA project and its science"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0811.2264","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":"sha256:8af6a54411f10fbe436f65240896727837503c34aa431a83eb6c0b84f3dec9a7","target":"record","created_at":"2026-05-18T02:35:13Z","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":"9a9f662ae17d2c539ab245246cea7619763c0de0ab2a352625410add9a1c71ba","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph","submitted_at":"2008-11-14T04:32:20Z","title_canon_sha256":"fa2b46b53656ee8b1723c0df2a452d598f1ac8f7e2d77b976cbd90cc1d2fd9f1"},"schema_version":"1.0","source":{"id":"0811.2264","kind":"arxiv","version":2}},"canonical_sha256":"8baf332b6b1d3291ead70287887c3e8dd847e0298deaf7c17c549ca47628ca3d","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"8baf332b6b1d3291ead70287887c3e8dd847e0298deaf7c17c549ca47628ca3d","first_computed_at":"2026-05-18T02:35:13.896294Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T02:35:13.896294Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"FVt5A/8RfmjSCPD+NYJJu7VDlfFoo+WwfByl19k8E928dg0Rvxb1J4Ik50Q3rNCri1FQEmB7LXWzKX/Vh+q3AA==","signature_status":"signed_v1","signed_at":"2026-05-18T02:35:13.896711Z","signed_message":"canonical_sha256_bytes"},"source_id":"0811.2264","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:8af6a54411f10fbe436f65240896727837503c34aa431a83eb6c0b84f3dec9a7","sha256:9160d4e664c588d3497b02e9b6854b8b24e687d5687066f23f744e3fc9e3aa08"],"state_sha256":"591d1d769eb9d14177faa255fcdd0978206a92e669aab5099e39783ad7608501"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"pMqPQfA46gjbfiOr5A8lv1UvxtDijN/aBOvIAEUdQhBeNuF8xYcqe+8rcq3K2mgYc48KjotPjbeqsItKC5CWAA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-22T14:17:34.102591Z","bundle_sha256":"991560c6b021d5629d54200724cecc49ad5a1fc3627eaf64e20ce7dd14c0c865"}}