{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2019:E5NKI6PKWH5TSSZCA2OXZL56F4","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":"c42236c63735be152d5d4c3e6786e806ed16b5035910823b54a10dfcd91ed2c2","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.HE","submitted_at":"2019-01-23T16:52:23Z","title_canon_sha256":"c83db9a5e537030b049a99d4c4ebb6cbb1c6a239f4422d48498a752efecb673a"},"schema_version":"1.0","source":{"id":"1901.07998","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1901.07998","created_at":"2026-05-17T23:48:30Z"},{"alias_kind":"arxiv_version","alias_value":"1901.07998v2","created_at":"2026-05-17T23:48:30Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1901.07998","created_at":"2026-05-17T23:48:30Z"},{"alias_kind":"pith_short_12","alias_value":"E5NKI6PKWH5T","created_at":"2026-05-18T12:33:15Z"},{"alias_kind":"pith_short_16","alias_value":"E5NKI6PKWH5TSSZC","created_at":"2026-05-18T12:33:15Z"},{"alias_kind":"pith_short_8","alias_value":"E5NKI6PK","created_at":"2026-05-18T12:33:15Z"}],"graph_snapshots":[{"event_id":"sha256:0e369c79122a818a730b6c67d53f137c1822eaf6ba1c64ee2ddedea0fae93f42","target":"graph","created_at":"2026-05-17T23:48:30Z","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 report non-detections of the $\\sim 3\\times 10^8$ yr old, slow, isolated, rotation-powered pulsar PSR J2144$-$3933 in observations with the Hubble Space Telescope in one optical band (F475X) and two far-ultraviolet bands (F125LP and F140LP), yielding upper bounds $F_{\\rm F475X}< 22.7$ nJy, $F_{\\rm F125LP}< 5.9$ nJy, $F_{\\rm F140LP}< 19.5$ nJy, at the pivot wavelengths 4940 \\AA, 1438 \\AA\\ and 1528 \\AA, respectively. Assuming a blackbody spectrum, we deduce a conservative upper bound on the surface (unredshifted) temperature of the pulsar of $T<42,000$ K. This makes PSR~J2144--3933 the coldest","authors_text":"A. Reisenegger, B. Rangelov, C. Reyes, G. G. Pavlov, L. Rodriguez, O. Kargaltsev, S. Guillot","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.HE","submitted_at":"2019-01-23T16:52:23Z","title":"Hubble Space Telescope non-detection of PSR J2144-3933: the coldest known neutron star"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1901.07998","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":"sha256:9684a8ad3b440f08afc885ce27492f261fca58ef92e27b06bcf17a6a34d8c8b4","target":"record","created_at":"2026-05-17T23:48:30Z","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":"c42236c63735be152d5d4c3e6786e806ed16b5035910823b54a10dfcd91ed2c2","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.HE","submitted_at":"2019-01-23T16:52:23Z","title_canon_sha256":"c83db9a5e537030b049a99d4c4ebb6cbb1c6a239f4422d48498a752efecb673a"},"schema_version":"1.0","source":{"id":"1901.07998","kind":"arxiv","version":2}},"canonical_sha256":"275aa479eab1fb394b22069d7cafbe2f193bd1d69dadedf63bdc409cd275d405","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"275aa479eab1fb394b22069d7cafbe2f193bd1d69dadedf63bdc409cd275d405","first_computed_at":"2026-05-17T23:48:30.774288Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-17T23:48:30.774288Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"os6s8vsGiMqIEYfEgtQLjy+aye0lKv9PUjPCDpbw5ZEWyyR15eT9hp09XNo0ZimHDwi3hGg1ErJ2wfD3xohHDQ==","signature_status":"signed_v1","signed_at":"2026-05-17T23:48:30.775117Z","signed_message":"canonical_sha256_bytes"},"source_id":"1901.07998","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:9684a8ad3b440f08afc885ce27492f261fca58ef92e27b06bcf17a6a34d8c8b4","sha256:0e369c79122a818a730b6c67d53f137c1822eaf6ba1c64ee2ddedea0fae93f42"],"state_sha256":"b476203ccd1bb57e2e4d93c522821ce66e10c6a7e3a428cf36429ba125f624c1"}