{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2026:76OV54BVGT3MTLD3EQHDLWYCTV","short_pith_number":"pith:76OV54BV","canonical_record":{"source":{"id":"2606.04624","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.SR","submitted_at":"2026-06-03T08:59:27Z","cross_cats_sorted":[],"title_canon_sha256":"60c18dc18da9fe141174259f034120c6fef74269229e20f6354e5c1a28477f23","abstract_canon_sha256":"abecb123ccd03503251e5e7f452712c47cdff993bd9c02e2c324925c9d11767d"},"schema_version":"1.0"},"canonical_sha256":"ff9d5ef03534f6c9ac7b240e35db029d5392e045f5af80b08469f2a209efd0e8","source":{"kind":"arxiv","id":"2606.04624","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2606.04624","created_at":"2026-06-04T01:09:21Z"},{"alias_kind":"arxiv_version","alias_value":"2606.04624v1","created_at":"2026-06-04T01:09:21Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2606.04624","created_at":"2026-06-04T01:09:21Z"},{"alias_kind":"pith_short_12","alias_value":"76OV54BVGT3M","created_at":"2026-06-04T01:09:21Z"},{"alias_kind":"pith_short_16","alias_value":"76OV54BVGT3MTLD3","created_at":"2026-06-04T01:09:21Z"},{"alias_kind":"pith_short_8","alias_value":"76OV54BV","created_at":"2026-06-04T01:09:21Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2026:76OV54BVGT3MTLD3EQHDLWYCTV","target":"record","payload":{"canonical_record":{"source":{"id":"2606.04624","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.SR","submitted_at":"2026-06-03T08:59:27Z","cross_cats_sorted":[],"title_canon_sha256":"60c18dc18da9fe141174259f034120c6fef74269229e20f6354e5c1a28477f23","abstract_canon_sha256":"abecb123ccd03503251e5e7f452712c47cdff993bd9c02e2c324925c9d11767d"},"schema_version":"1.0"},"canonical_sha256":"ff9d5ef03534f6c9ac7b240e35db029d5392e045f5af80b08469f2a209efd0e8","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-06-04T01:09:21.917575Z","signature_b64":"xFMR1sOhcsHVYK5Md8dB3A4nBx8lxNQhc3fYKr0Ad26KbnpckHf+ZzPq3SQsio446doymtExVmIGqQ8rpvWoBA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"ff9d5ef03534f6c9ac7b240e35db029d5392e045f5af80b08469f2a209efd0e8","last_reissued_at":"2026-06-04T01:09:21.916834Z","signature_status":"signed_v1","first_computed_at":"2026-06-04T01:09:21.916834Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2606.04624","source_version":1,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-06-04T01:09:21Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"+kKwhaq6IQ5wfHOCvwIrHqD9X6pd4hrGfITe2ECPrJhvknUh3knLH4ZqtLR88qTCa4gjuAIYbPrddnm9J0AeCA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-04T18:01:07.700256Z"},"content_sha256":"4d54884538ae352d1d2af3ef0d00848f1728722df742646718711a019cc452c5","schema_version":"1.0","event_id":"sha256:4d54884538ae352d1d2af3ef0d00848f1728722df742646718711a019cc452c5"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2026:76OV54BVGT3MTLD3EQHDLWYCTV","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Blue Straggler Stars in Berkeley 18: A Multiwavelength Study of Their Physical Properties and Dynamical Evolution","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.SR","authors_text":"Alok Durgapal, A. Raj, D. Bisht, D. C. \\c{C}{\\i}nar, Geeta Rangwal, Ing-Guey Jiang, K. Belwal, M. Manu, M. S. Bisht, Shraddha Biswas","submitted_at":"2026-06-03T08:59:27Z","abstract_excerpt":"Berkeley~18 is an old open cluster in the outer Galactic disk that hosts a population of blue straggler stars (BSSs). We present a comprehensive multiwavelength analysis of its BSS population using \\textit{Gaia} DR3 astrometry, optical--infrared photometry, and time-domain TESS observations. Using a Gaussian Mixture Model (GMM) in astrometric space, we identify 798 high-probability cluster members ($p > 0.7$). Isochrone fitting yields an age of $3.2 \\pm 0.2$ Gyr and a heliocentric distance of $5.01^{+0.75}_{-0.55}$ kpc. We identify 24 BSS candidates above the main-sequence turn-off. Spectral e"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2606.04624","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/2606.04624/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"},"verdict_id":null},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-06-04T01:09:21Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"mrEtrn5Z/kFaROucPdmZD7gTFPIOpwu36sYfCusUJoJAvz+vA6kN+FMaZkyZyaySuDJawDOCUdltG0Avs8gtDA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-04T18:01:07.700654Z"},"content_sha256":"7f3e865a345ef9526cded47a680402b2689160b37f2c89cd5892406724d5f7a3","schema_version":"1.0","event_id":"sha256:7f3e865a345ef9526cded47a680402b2689160b37f2c89cd5892406724d5f7a3"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/76OV54BVGT3MTLD3EQHDLWYCTV/bundle.json","state_url":"https://pith.science/pith/76OV54BVGT3MTLD3EQHDLWYCTV/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/76OV54BVGT3MTLD3EQHDLWYCTV/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":"2026-06-04T18:01:07Z","links":{"resolver":"https://pith.science/pith/76OV54BVGT3MTLD3EQHDLWYCTV","bundle":"https://pith.science/pith/76OV54BVGT3MTLD3EQHDLWYCTV/bundle.json","state":"https://pith.science/pith/76OV54BVGT3MTLD3EQHDLWYCTV/state.json","well_known_bundle":"https://pith.science/.well-known/pith/76OV54BVGT3MTLD3EQHDLWYCTV/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2026:76OV54BVGT3MTLD3EQHDLWYCTV","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":"abecb123ccd03503251e5e7f452712c47cdff993bd9c02e2c324925c9d11767d","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.SR","submitted_at":"2026-06-03T08:59:27Z","title_canon_sha256":"60c18dc18da9fe141174259f034120c6fef74269229e20f6354e5c1a28477f23"},"schema_version":"1.0","source":{"id":"2606.04624","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2606.04624","created_at":"2026-06-04T01:09:21Z"},{"alias_kind":"arxiv_version","alias_value":"2606.04624v1","created_at":"2026-06-04T01:09:21Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2606.04624","created_at":"2026-06-04T01:09:21Z"},{"alias_kind":"pith_short_12","alias_value":"76OV54BVGT3M","created_at":"2026-06-04T01:09:21Z"},{"alias_kind":"pith_short_16","alias_value":"76OV54BVGT3MTLD3","created_at":"2026-06-04T01:09:21Z"},{"alias_kind":"pith_short_8","alias_value":"76OV54BV","created_at":"2026-06-04T01:09:21Z"}],"graph_snapshots":[{"event_id":"sha256:7f3e865a345ef9526cded47a680402b2689160b37f2c89cd5892406724d5f7a3","target":"graph","created_at":"2026-06-04T01:09:21Z","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"},"integrity":{"available":true,"clean":true,"detectors_run":[],"endpoint":"/pith/2606.04624/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"Berkeley~18 is an old open cluster in the outer Galactic disk that hosts a population of blue straggler stars (BSSs). We present a comprehensive multiwavelength analysis of its BSS population using \\textit{Gaia} DR3 astrometry, optical--infrared photometry, and time-domain TESS observations. Using a Gaussian Mixture Model (GMM) in astrometric space, we identify 798 high-probability cluster members ($p > 0.7$). Isochrone fitting yields an age of $3.2 \\pm 0.2$ Gyr and a heliocentric distance of $5.01^{+0.75}_{-0.55}$ kpc. We identify 24 BSS candidates above the main-sequence turn-off. Spectral e","authors_text":"Alok Durgapal, A. Raj, D. Bisht, D. C. \\c{C}{\\i}nar, Geeta Rangwal, Ing-Guey Jiang, K. Belwal, M. Manu, M. S. Bisht, Shraddha Biswas","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.SR","submitted_at":"2026-06-03T08:59:27Z","title":"Blue Straggler Stars in Berkeley 18: A Multiwavelength Study of Their Physical Properties and Dynamical Evolution"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2606.04624","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":"sha256:4d54884538ae352d1d2af3ef0d00848f1728722df742646718711a019cc452c5","target":"record","created_at":"2026-06-04T01:09:21Z","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":"abecb123ccd03503251e5e7f452712c47cdff993bd9c02e2c324925c9d11767d","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.SR","submitted_at":"2026-06-03T08:59:27Z","title_canon_sha256":"60c18dc18da9fe141174259f034120c6fef74269229e20f6354e5c1a28477f23"},"schema_version":"1.0","source":{"id":"2606.04624","kind":"arxiv","version":1}},"canonical_sha256":"ff9d5ef03534f6c9ac7b240e35db029d5392e045f5af80b08469f2a209efd0e8","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"ff9d5ef03534f6c9ac7b240e35db029d5392e045f5af80b08469f2a209efd0e8","first_computed_at":"2026-06-04T01:09:21.916834Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-06-04T01:09:21.916834Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"xFMR1sOhcsHVYK5Md8dB3A4nBx8lxNQhc3fYKr0Ad26KbnpckHf+ZzPq3SQsio446doymtExVmIGqQ8rpvWoBA==","signature_status":"signed_v1","signed_at":"2026-06-04T01:09:21.917575Z","signed_message":"canonical_sha256_bytes"},"source_id":"2606.04624","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:4d54884538ae352d1d2af3ef0d00848f1728722df742646718711a019cc452c5","sha256:7f3e865a345ef9526cded47a680402b2689160b37f2c89cd5892406724d5f7a3"],"state_sha256":"4b063c77044e4397bd135b93869cadaf72fdc0c3686631c62eb804016c13ccd5"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"RTb+oUN0Qy8fM9qKIP8TKCUl05Ly8Ad2nb4K6MEXy30Q5e1xS1StX8AW8ES9nwycHSt21ntFnyr9YxLF/d9HBQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-04T18:01:07.702753Z","bundle_sha256":"65eb6d29c2bda6d7509afcfd3c0edbe39e0f9d0b10ea826000f3c503c740e261"}}