{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2015:R6FCW2WVLGMH7YA7WY55I4AXWP","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":"87fa20457fc52d00b8fd6f001ddfc9f2604a0f3f3c4c1c16babd3863b8ec7d38","cross_cats_sorted":["astro-ph.EP"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.SR","submitted_at":"2015-09-29T12:35:25Z","title_canon_sha256":"4c9afaf6ef15d16d5961223e3d623b4dee4cf9d81a95bdb5a3fbb0733a429697"},"schema_version":"1.0","source":{"id":"1509.08718","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1509.08718","created_at":"2026-05-18T01:27:22Z"},{"alias_kind":"arxiv_version","alias_value":"1509.08718v1","created_at":"2026-05-18T01:27:22Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1509.08718","created_at":"2026-05-18T01:27:22Z"},{"alias_kind":"pith_short_12","alias_value":"R6FCW2WVLGMH","created_at":"2026-05-18T12:29:39Z"},{"alias_kind":"pith_short_16","alias_value":"R6FCW2WVLGMH7YA7","created_at":"2026-05-18T12:29:39Z"},{"alias_kind":"pith_short_8","alias_value":"R6FCW2WV","created_at":"2026-05-18T12:29:39Z"}],"graph_snapshots":[{"event_id":"sha256:6ef820c4a8a3f8461904ba08900601d14ebf0c2756d8687aadfba60077eed3ed","target":"graph","created_at":"2026-05-18T01:27:22Z","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 the OSIRIS camera at the 10.4 m Gran Telescopio Canarias (GTC) to monitor the astrometric motion of the L4.5 dwarf 2M1821$+$14 over 17 months. The astrometric residuals of eleven epochs have a r.m.s. dispersion of 0.4 mas, which is larger than the average precision of 0.23 mas per epoch and hints towards an additional signal or excess noise. Comparison of the point-spread-functions in OSIRIS and FORS2/VLT images reveals no differences critical for high-precision astrometry, despite the GTC's segmented primary mirror. We attribute the excess noise to an unknown effect that may be uncove","authors_text":"D. Queloz, D. S\\'egransan, E. L. Mart\\'in, H. Bouy, J. Sahlmann, M. R. Zapatero Osorio, P. F. Lazorenko","cross_cats":["astro-ph.EP"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.SR","submitted_at":"2015-09-29T12:35:25Z","title":"Parallax of the L4.5 dwarf 2M1821$+$14 from high-precision astrometry with OSIRIS at GTC"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1509.08718","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":"sha256:47b89b268e5e19db3e956f475659b3d603d806d0f8e9d61c91969bfa9ab2f7ff","target":"record","created_at":"2026-05-18T01:27:22Z","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":"87fa20457fc52d00b8fd6f001ddfc9f2604a0f3f3c4c1c16babd3863b8ec7d38","cross_cats_sorted":["astro-ph.EP"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.SR","submitted_at":"2015-09-29T12:35:25Z","title_canon_sha256":"4c9afaf6ef15d16d5961223e3d623b4dee4cf9d81a95bdb5a3fbb0733a429697"},"schema_version":"1.0","source":{"id":"1509.08718","kind":"arxiv","version":1}},"canonical_sha256":"8f8a2b6ad559987fe01fb63bd47017b3e92e8bc055f388362d37f9cd22ac4983","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"8f8a2b6ad559987fe01fb63bd47017b3e92e8bc055f388362d37f9cd22ac4983","first_computed_at":"2026-05-18T01:27:22.429368Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T01:27:22.429368Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"GR6qNMn9GAxD50tXQr6VrT8ZmjmGxIks0MBDa9VRmM0nzLvF+/r5onsxZe7aMhB0ZT7jt6JEcnzu37AYhUKbDw==","signature_status":"signed_v1","signed_at":"2026-05-18T01:27:22.429883Z","signed_message":"canonical_sha256_bytes"},"source_id":"1509.08718","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:47b89b268e5e19db3e956f475659b3d603d806d0f8e9d61c91969bfa9ab2f7ff","sha256:6ef820c4a8a3f8461904ba08900601d14ebf0c2756d8687aadfba60077eed3ed"],"state_sha256":"2b0f68db26aec531aea0bbb7fd0909a837cac9a7dc7ab08f79d5e5413faa122f"}