{"record_type":"pith_number_record","schema_url":"https://pith.science/schemas/pith-number/v1.json","pith_number":"pith:2009:XIMILEKOVLPJNVIEHZ5FCFKADD","short_pith_number":"pith:XIMILEKO","schema_version":"1.0","canonical_sha256":"ba1885914eaade96d5043e7a51154018cb4b22a5b93d6904d80e1aeea3032ac6","source":{"kind":"arxiv","id":"0909.1746","version":1},"attestation_state":"computed","paper":{"title":"New Methods for Determining the Ages of PMS Stars","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.IM"],"primary_cat":"astro-ph.SR","authors_text":"Eric S. Saunders, N.J. Mayne, R.D. Jeffries, S.P. Littlefair, Tim Naylor","submitted_at":"2009-09-09T17:07:54Z","abstract_excerpt":"We present three new methods for determining the age of groups of pre-main-sequence stars. The first, creating empirical isochrones allows us to create a robust age ordering, but not to derive actual ages. The second, using the width of the gap in colour-magnitude space between the pre-main-sequence and main-sequence (the radiative convective gap) has promise as a distance and extinction independent measure of age, but is as yet uncalibrated. Finally we discuss tau-squared fitting of the main sequence as the stars approach the terminus of the main sequence. This method suggests that there is a"},"verification_status":{"content_addressed":true,"pith_receipt":true,"author_attested":false,"weak_author_claims":0,"strong_author_claims":0,"externally_anchored":false,"storage_verified":false,"citation_signatures":0,"replication_records":0,"graph_snapshot":true,"references_resolved":false,"formal_links_present":false},"canonical_record":{"source":{"id":"0909.1746","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.SR","submitted_at":"2009-09-09T17:07:54Z","cross_cats_sorted":["astro-ph.IM"],"title_canon_sha256":"5da9c24fe8c2a1beb24dbd650aec53d4e86b25b30da1407821e5ecdddb762157","abstract_canon_sha256":"01d1a27f4543cd53b1ba08765e89749fadb764233ead97802ecfb7ceffe57327"},"schema_version":"1.0"},"receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-04T15:49:10.723432Z","signature_b64":"Sc+Xp/ElwnkD+4Bsl7BLk/YJGVa0TJOum4iNPLHm7/k9sFumIcSGDWcblADUh7OmFQPORXhuzAHUXJC7+RsWAw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"ba1885914eaade96d5043e7a51154018cb4b22a5b93d6904d80e1aeea3032ac6","last_reissued_at":"2026-07-04T15:49:10.723032Z","signature_status":"signed_v1","first_computed_at":"2026-07-04T15:49:10.723032Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"graph_snapshot":{"paper":{"title":"New Methods for Determining the Ages of PMS Stars","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.IM"],"primary_cat":"astro-ph.SR","authors_text":"Eric S. Saunders, N.J. Mayne, R.D. Jeffries, S.P. Littlefair, Tim Naylor","submitted_at":"2009-09-09T17:07:54Z","abstract_excerpt":"We present three new methods for determining the age of groups of pre-main-sequence stars. The first, creating empirical isochrones allows us to create a robust age ordering, but not to derive actual ages. The second, using the width of the gap in colour-magnitude space between the pre-main-sequence and main-sequence (the radiative convective gap) has promise as a distance and extinction independent measure of age, but is as yet uncalibrated. Finally we discuss tau-squared fitting of the main sequence as the stars approach the terminus of the main sequence. This method suggests that there is a"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0909.1746","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":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/0909.1746/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"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"},"aliases":[{"alias_kind":"arxiv","alias_value":"0909.1746","created_at":"2026-07-04T15:49:10.723092+00:00"},{"alias_kind":"arxiv_version","alias_value":"0909.1746v1","created_at":"2026-07-04T15:49:10.723092+00:00"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.0909.1746","created_at":"2026-07-04T15:49:10.723092+00:00"},{"alias_kind":"pith_short_12","alias_value":"XIMILEKOVLPJ","created_at":"2026-07-04T15:49:10.723092+00:00"},{"alias_kind":"pith_short_16","alias_value":"XIMILEKOVLPJNVIE","created_at":"2026-07-04T15:49:10.723092+00:00"},{"alias_kind":"pith_short_8","alias_value":"XIMILEKO","created_at":"2026-07-04T15:49:10.723092+00:00"}],"events":[],"event_summary":{},"paper_claims":[],"inbound_citations":{"count":0,"internal_anchor_count":0,"sample":[]},"formal_canon":{"evidence_count":0,"sample":[],"anchors":[]},"links":{"html":"https://pith.science/pith/XIMILEKOVLPJNVIEHZ5FCFKADD","json":"https://pith.science/pith/XIMILEKOVLPJNVIEHZ5FCFKADD.json","graph_json":"https://pith.science/api/pith-number/XIMILEKOVLPJNVIEHZ5FCFKADD/graph.json","events_json":"https://pith.science/api/pith-number/XIMILEKOVLPJNVIEHZ5FCFKADD/events.json","paper":"https://pith.science/paper/XIMILEKO"},"agent_actions":{"view_html":"https://pith.science/pith/XIMILEKOVLPJNVIEHZ5FCFKADD","download_json":"https://pith.science/pith/XIMILEKOVLPJNVIEHZ5FCFKADD.json","view_paper":"https://pith.science/paper/XIMILEKO","resolve_alias":"https://pith.science/api/pith-number/resolve?arxiv=0909.1746&json=true","fetch_graph":"https://pith.science/api/pith-number/XIMILEKOVLPJNVIEHZ5FCFKADD/graph.json","fetch_events":"https://pith.science/api/pith-number/XIMILEKOVLPJNVIEHZ5FCFKADD/events.json","actions":{"anchor_timestamp":"https://pith.science/pith/XIMILEKOVLPJNVIEHZ5FCFKADD/action/timestamp_anchor","attest_storage":"https://pith.science/pith/XIMILEKOVLPJNVIEHZ5FCFKADD/action/storage_attestation","attest_author":"https://pith.science/pith/XIMILEKOVLPJNVIEHZ5FCFKADD/action/author_attestation","sign_citation":"https://pith.science/pith/XIMILEKOVLPJNVIEHZ5FCFKADD/action/citation_signature","submit_replication":"https://pith.science/pith/XIMILEKOVLPJNVIEHZ5FCFKADD/action/replication_record"}},"created_at":"2026-07-04T15:49:10.723092+00:00","updated_at":"2026-07-04T15:49:10.723092+00:00"}