{"record_type":"pith_number_record","schema_url":"https://pith.science/schemas/pith-number/v1.json","pith_number":"pith:2026:QCUY2M7VHKV4WXWB7B2NPVDUUY","short_pith_number":"pith:QCUY2M7V","schema_version":"1.0","canonical_sha256":"80a98d33f53aabcb5ec1f874d7d474a610b8d244a420177d8ab83b9279196105","source":{"kind":"arxiv","id":"2604.03142","version":1},"attestation_state":"computed","paper":{"title":"Isochrone-cloud fitting and asteroseismology of the Kepler open cluster NGC6866","license":"http://creativecommons.org/licenses/by/4.0/","headline":"Age dating of open cluster NGC 6866 varies from 467 to 759 million years depending on the stellar models and initial conditions chosen.","cross_cats":["astro-ph.GA"],"primary_cat":"astro-ph.SR","authors_text":"Conny Aerts, Dario J. Fritzewski, Gang Li, Haotian Wang, Timothy Van Reeth","submitted_at":"2026-04-03T16:04:04Z","abstract_excerpt":"We investigate how isochrones computed with different input physics and initial conditions affect the age dating of the open cluster NGC 6866, and compare the results with asteroseismic ages derived from Kepler photometry. Using Gaia DR3 data, we identified 180 cluster members with a clustering algorithm. We then developed an isochrone-cloud fitting method that accounts for a range of free parameters in the input physics. Variable stars were subsequently identified among the cluster members. For 19 g-mode pulsators, we carried out modelling with a dedicated grid of rotating stellar models, con"},"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":true,"formal_links_present":false},"canonical_record":{"source":{"id":"2604.03142","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.SR","submitted_at":"2026-04-03T16:04:04Z","cross_cats_sorted":["astro-ph.GA"],"title_canon_sha256":"6673a2b647f83503d3b15531ab9d52fb917f44b770bfe13464577b1887fbbe25","abstract_canon_sha256":"b482f0f85ca3a3296bdc53349a392c58c6a1464e4c81f9c1e0436b16258e3658"},"schema_version":"1.0"},"receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-06-10T14:10:49.010901Z","signature_b64":"uOF2/SjKDPyEzn/bRAk0nPyHVAVNjQXO89Z9dZVci2u3CTS3Df+wzvyEMgN5jWRsAmS3vCq7rJwFLLXANsxAAQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"80a98d33f53aabcb5ec1f874d7d474a610b8d244a420177d8ab83b9279196105","last_reissued_at":"2026-06-10T14:10:49.010027Z","signature_status":"signed_v1","first_computed_at":"2026-06-10T14:10:49.010027Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"graph_snapshot":{"paper":{"title":"Isochrone-cloud fitting and asteroseismology of the Kepler open cluster NGC6866","license":"http://creativecommons.org/licenses/by/4.0/","headline":"Age dating of open cluster NGC 6866 varies from 467 to 759 million years depending on the stellar models and initial conditions chosen.","cross_cats":["astro-ph.GA"],"primary_cat":"astro-ph.SR","authors_text":"Conny Aerts, Dario J. Fritzewski, Gang Li, Haotian Wang, Timothy Van Reeth","submitted_at":"2026-04-03T16:04:04Z","abstract_excerpt":"We investigate how isochrones computed with different input physics and initial conditions affect the age dating of the open cluster NGC 6866, and compare the results with asteroseismic ages derived from Kepler photometry. Using Gaia DR3 data, we identified 180 cluster members with a clustering algorithm. We then developed an isochrone-cloud fitting method that accounts for a range of free parameters in the input physics. Variable stars were subsequently identified among the cluster members. For 19 g-mode pulsators, we carried out modelling with a dedicated grid of rotating stellar models, con"},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"We conclude that age dating of open clusters is sensitive to the adopted input physics and initial conditions, highlighting the need for better calibrated stellar evolutionary models.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"The assumption that the 180 Gaia-selected members are free of significant field-star contamination and that the asteroseismic grid accurately captures the effects of internal mixing and rotation without unaccounted systematic biases in the underlying stellar models.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"Isochrone fitting and asteroseismology of NGC 6866 yield cluster ages from 467 Myr (MIST) to 759 Myr (PARSEC with shared seismic age), demonstrating sensitivity to input physics and initial rotation.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"Age dating of open cluster NGC 6866 varies from 467 to 759 million years depending on the stellar models and initial conditions chosen.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"809325a194b688a4071be7379ef0cd7562cbdf3e2af930773c442c75b75c3be6"},"source":{"id":"2604.03142","kind":"arxiv","version":1},"verdict":{"id":"c41c3604-032b-4e23-a873-f558b4aaab46","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-13T18:54:19.215127Z","strongest_claim":"We conclude that age dating of open clusters is sensitive to the adopted input physics and initial conditions, highlighting the need for better calibrated stellar evolutionary models.","one_line_summary":"Isochrone fitting and asteroseismology of NGC 6866 yield cluster ages from 467 Myr (MIST) to 759 Myr (PARSEC with shared seismic age), demonstrating sensitivity to input physics and initial rotation.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"The assumption that the 180 Gaia-selected members are free of significant field-star contamination and that the asteroseismic grid accurately captures the effects of internal mixing and rotation without unaccounted systematic biases in the underlying stellar models.","pith_extraction_headline":"Age dating of open cluster NGC 6866 varies from 467 to 759 million years depending on the stellar models and initial conditions chosen."},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2604.03142/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":4,"sample":[{"doi":"","year":null,"title":"Critical sampling constraint: The rotation rates, expressed as the ratio of Keplerian critical speed (v/v crit), range from 0 to 0.9 with a step size of 0.1","work_id":"fcd966be-0788-49e2-93c1-05e9525156c2","ref_index":1,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":null,"title":"Normalisation condition: The sum of the fractions of stars with different initial rotations must equal 1","work_id":"bd48cf0f-a8ad-4a4c-b930-d1c8861bfb35","ref_index":2,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":null,"title":"Multiplicity requirement: Each rotation distribution must contain at least three distinct initial rotation values","work_id":"330ef5ae-e017-403f-97d8-cd19b6414b3a","ref_index":3,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2023,"title":"This results in a total of 72 possible distributions","work_id":"612529c5-02b3-4a7d-b620-2e904dd82ccd","ref_index":4,"cited_arxiv_id":"","is_internal_anchor":false}],"resolved_work":4,"snapshot_sha256":"5a3ccc0ebde7247c5156f4eb9b30e94beb7098f784da994792249f366cb57707","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":"2604.03142","created_at":"2026-06-10T14:10:49.010149+00:00"},{"alias_kind":"arxiv_version","alias_value":"2604.03142v1","created_at":"2026-06-10T14:10:49.010149+00:00"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2604.03142","created_at":"2026-06-10T14:10:49.010149+00:00"},{"alias_kind":"pith_short_12","alias_value":"QCUY2M7VHKV4","created_at":"2026-06-10T14:10:49.010149+00:00"},{"alias_kind":"pith_short_16","alias_value":"QCUY2M7VHKV4WXWB","created_at":"2026-06-10T14:10:49.010149+00:00"},{"alias_kind":"pith_short_8","alias_value":"QCUY2M7V","created_at":"2026-06-10T14:10:49.010149+00:00"}],"events":[],"event_summary":{},"paper_claims":[],"inbound_citations":{"count":1,"internal_anchor_count":1,"sample":[{"citing_arxiv_id":"2604.12758","citing_title":"Variability classification of TESS targets in LOPS2, the first long-term pointing field of PLATO. Version 1 of the public variability catalogue","ref_index":107,"is_internal_anchor":true}]},"formal_canon":{"evidence_count":0,"sample":[],"anchors":[]},"links":{"html":"https://pith.science/pith/QCUY2M7VHKV4WXWB7B2NPVDUUY","json":"https://pith.science/pith/QCUY2M7VHKV4WXWB7B2NPVDUUY.json","graph_json":"https://pith.science/api/pith-number/QCUY2M7VHKV4WXWB7B2NPVDUUY/graph.json","events_json":"https://pith.science/api/pith-number/QCUY2M7VHKV4WXWB7B2NPVDUUY/events.json","paper":"https://pith.science/paper/QCUY2M7V"},"agent_actions":{"view_html":"https://pith.science/pith/QCUY2M7VHKV4WXWB7B2NPVDUUY","download_json":"https://pith.science/pith/QCUY2M7VHKV4WXWB7B2NPVDUUY.json","view_paper":"https://pith.science/paper/QCUY2M7V","resolve_alias":"https://pith.science/api/pith-number/resolve?arxiv=2604.03142&json=true","fetch_graph":"https://pith.science/api/pith-number/QCUY2M7VHKV4WXWB7B2NPVDUUY/graph.json","fetch_events":"https://pith.science/api/pith-number/QCUY2M7VHKV4WXWB7B2NPVDUUY/events.json","actions":{"anchor_timestamp":"https://pith.science/pith/QCUY2M7VHKV4WXWB7B2NPVDUUY/action/timestamp_anchor","attest_storage":"https://pith.science/pith/QCUY2M7VHKV4WXWB7B2NPVDUUY/action/storage_attestation","attest_author":"https://pith.science/pith/QCUY2M7VHKV4WXWB7B2NPVDUUY/action/author_attestation","sign_citation":"https://pith.science/pith/QCUY2M7VHKV4WXWB7B2NPVDUUY/action/citation_signature","submit_replication":"https://pith.science/pith/QCUY2M7VHKV4WXWB7B2NPVDUUY/action/replication_record"}},"created_at":"2026-06-10T14:10:49.010149+00:00","updated_at":"2026-06-10T14:10:49.010149+00:00"}