{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2020:HQPWSKVZ6DO2MR2JAAC2XA3XVH","short_pith_number":"pith:HQPWSKVZ","canonical_record":{"source":{"id":"2003.00028","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.SR","submitted_at":"2020-02-28T19:10:56Z","cross_cats_sorted":[],"title_canon_sha256":"b64babb344e5a15bea3b7a00e2127fcc5c79bd1f842c2c1a900c859e84e42038","abstract_canon_sha256":"656a9968f7b761adb0dab405ba33382e90a5ba858c677d2319feab98564cda46"},"schema_version":"1.0"},"canonical_sha256":"3c1f692ab9f0dda647490005ab8377a9e0876b3c67c9fe76ffc91f6562eca4a6","source":{"kind":"arxiv","id":"2003.00028","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2003.00028","created_at":"2026-07-05T00:44:43Z"},{"alias_kind":"arxiv_version","alias_value":"2003.00028v1","created_at":"2026-07-05T00:44:43Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2003.00028","created_at":"2026-07-05T00:44:43Z"},{"alias_kind":"pith_short_12","alias_value":"HQPWSKVZ6DO2","created_at":"2026-07-05T00:44:43Z"},{"alias_kind":"pith_short_16","alias_value":"HQPWSKVZ6DO2MR2J","created_at":"2026-07-05T00:44:43Z"},{"alias_kind":"pith_short_8","alias_value":"HQPWSKVZ","created_at":"2026-07-05T00:44:43Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2020:HQPWSKVZ6DO2MR2JAAC2XA3XVH","target":"record","payload":{"canonical_record":{"source":{"id":"2003.00028","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.SR","submitted_at":"2020-02-28T19:10:56Z","cross_cats_sorted":[],"title_canon_sha256":"b64babb344e5a15bea3b7a00e2127fcc5c79bd1f842c2c1a900c859e84e42038","abstract_canon_sha256":"656a9968f7b761adb0dab405ba33382e90a5ba858c677d2319feab98564cda46"},"schema_version":"1.0"},"canonical_sha256":"3c1f692ab9f0dda647490005ab8377a9e0876b3c67c9fe76ffc91f6562eca4a6","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T00:44:43.394303Z","signature_b64":"MQWA2MvhpsCkxBtn2AihlrZRFxYcwEpwMz3ReAdZhlW4sZjPo+amCFtr+pI4nv6A7w7rQ8qPyGE8BAMEEyINBg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"3c1f692ab9f0dda647490005ab8377a9e0876b3c67c9fe76ffc91f6562eca4a6","last_reissued_at":"2026-07-05T00:44:43.393843Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T00:44:43.393843Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2003.00028","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":"2026-07-05T00:44:43Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"x4CUq3ibanF5mDsgEPtN/ozCDZB0F+aoUiHPtfiLF0FYcIsxFXC7w4+nxHA0ZLj/EmbS+tsuWzUsFODA+SqzCw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-07T00:28:10.444146Z"},"content_sha256":"d4fdd066ea2c327f1fc04584eba4d2851ee347c2cfbec92d13a0fc67c8238721","schema_version":"1.0","event_id":"sha256:d4fdd066ea2c327f1fc04584eba4d2851ee347c2cfbec92d13a0fc67c8238721"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2020:HQPWSKVZ6DO2MR2JAAC2XA3XVH","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"An ultra-massive white dwarf with a mixed hydrogen-carbon atmosphere as a likely merger remnant","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.SR","authors_text":"Alejandro H. C\\'orsico, Amornrat Aungwerojwit, Boris T. G\\\"ansicke, Danny Steeghs, Detlev Koester, Mar\\'ia E. Camisassa, Mark A. Hollands, Matthew J. Hoskin, Nicola P. Gentile-Fusillo, Paula Izquierdo, Paul Chote, Pier-Emmanuel Tremblay, Tom R. Marsh, Vik S. Dhillon","submitted_at":"2020-02-28T19:10:56Z","abstract_excerpt":"White dwarfs are dense, cooling stellar embers consisting mostly of carbon and oxygen, or oxygen and neon (with a few percent carbon) at higher initial stellar masses. These stellar cores are enveloped by a shell of helium which in turn is usually surrounded by a layer of hydrogen, generally prohibiting direct observation of the interior composition. However, carbon is observed at the surface of a sizeable fraction of white dwarfs, sometimes with traces of oxygen, and it is thought to be dredged-up from the core by a deep helium convection zone. In these objects only traces of hydrogen are fou"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2003.00028","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/2003.00028/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":"2026-07-05T00:44:43Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"OexFmYMC5bQJBfBQGZWiQOikGwi6otVOIj+xACYyMzoxkYiyGYrV/2XUhuyB2JT/JyasSqxVXVOZG+vkcAYdCA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-07T00:28:10.444951Z"},"content_sha256":"3edb30fb1d8bb7a2af1dac7e931a551493cf9fb85c71d04d081dd8ce5c7da5a5","schema_version":"1.0","event_id":"sha256:3edb30fb1d8bb7a2af1dac7e931a551493cf9fb85c71d04d081dd8ce5c7da5a5"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/HQPWSKVZ6DO2MR2JAAC2XA3XVH/bundle.json","state_url":"https://pith.science/pith/HQPWSKVZ6DO2MR2JAAC2XA3XVH/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/HQPWSKVZ6DO2MR2JAAC2XA3XVH/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":"2026-08-07T00:28:10Z","links":{"resolver":"https://pith.science/pith/HQPWSKVZ6DO2MR2JAAC2XA3XVH","bundle":"https://pith.science/pith/HQPWSKVZ6DO2MR2JAAC2XA3XVH/bundle.json","state":"https://pith.science/pith/HQPWSKVZ6DO2MR2JAAC2XA3XVH/state.json","well_known_bundle":"https://pith.science/.well-known/pith/HQPWSKVZ6DO2MR2JAAC2XA3XVH/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2020:HQPWSKVZ6DO2MR2JAAC2XA3XVH","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":"656a9968f7b761adb0dab405ba33382e90a5ba858c677d2319feab98564cda46","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.SR","submitted_at":"2020-02-28T19:10:56Z","title_canon_sha256":"b64babb344e5a15bea3b7a00e2127fcc5c79bd1f842c2c1a900c859e84e42038"},"schema_version":"1.0","source":{"id":"2003.00028","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2003.00028","created_at":"2026-07-05T00:44:43Z"},{"alias_kind":"arxiv_version","alias_value":"2003.00028v1","created_at":"2026-07-05T00:44:43Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2003.00028","created_at":"2026-07-05T00:44:43Z"},{"alias_kind":"pith_short_12","alias_value":"HQPWSKVZ6DO2","created_at":"2026-07-05T00:44:43Z"},{"alias_kind":"pith_short_16","alias_value":"HQPWSKVZ6DO2MR2J","created_at":"2026-07-05T00:44:43Z"},{"alias_kind":"pith_short_8","alias_value":"HQPWSKVZ","created_at":"2026-07-05T00:44:43Z"}],"graph_snapshots":[{"event_id":"sha256:3edb30fb1d8bb7a2af1dac7e931a551493cf9fb85c71d04d081dd8ce5c7da5a5","target":"graph","created_at":"2026-07-05T00:44:43Z","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/2003.00028/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"White dwarfs are dense, cooling stellar embers consisting mostly of carbon and oxygen, or oxygen and neon (with a few percent carbon) at higher initial stellar masses. These stellar cores are enveloped by a shell of helium which in turn is usually surrounded by a layer of hydrogen, generally prohibiting direct observation of the interior composition. However, carbon is observed at the surface of a sizeable fraction of white dwarfs, sometimes with traces of oxygen, and it is thought to be dredged-up from the core by a deep helium convection zone. In these objects only traces of hydrogen are fou","authors_text":"Alejandro H. C\\'orsico, Amornrat Aungwerojwit, Boris T. G\\\"ansicke, Danny Steeghs, Detlev Koester, Mar\\'ia E. Camisassa, Mark A. Hollands, Matthew J. Hoskin, Nicola P. Gentile-Fusillo, Paula Izquierdo, Paul Chote, Pier-Emmanuel Tremblay, Tom R. Marsh, Vik S. Dhillon","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.SR","submitted_at":"2020-02-28T19:10:56Z","title":"An ultra-massive white dwarf with a mixed hydrogen-carbon atmosphere as a likely merger remnant"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2003.00028","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:d4fdd066ea2c327f1fc04584eba4d2851ee347c2cfbec92d13a0fc67c8238721","target":"record","created_at":"2026-07-05T00:44:43Z","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":"656a9968f7b761adb0dab405ba33382e90a5ba858c677d2319feab98564cda46","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.SR","submitted_at":"2020-02-28T19:10:56Z","title_canon_sha256":"b64babb344e5a15bea3b7a00e2127fcc5c79bd1f842c2c1a900c859e84e42038"},"schema_version":"1.0","source":{"id":"2003.00028","kind":"arxiv","version":1}},"canonical_sha256":"3c1f692ab9f0dda647490005ab8377a9e0876b3c67c9fe76ffc91f6562eca4a6","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"3c1f692ab9f0dda647490005ab8377a9e0876b3c67c9fe76ffc91f6562eca4a6","first_computed_at":"2026-07-05T00:44:43.393843Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T00:44:43.393843Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"MQWA2MvhpsCkxBtn2AihlrZRFxYcwEpwMz3ReAdZhlW4sZjPo+amCFtr+pI4nv6A7w7rQ8qPyGE8BAMEEyINBg==","signature_status":"signed_v1","signed_at":"2026-07-05T00:44:43.394303Z","signed_message":"canonical_sha256_bytes"},"source_id":"2003.00028","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:d4fdd066ea2c327f1fc04584eba4d2851ee347c2cfbec92d13a0fc67c8238721","sha256:3edb30fb1d8bb7a2af1dac7e931a551493cf9fb85c71d04d081dd8ce5c7da5a5"],"state_sha256":"67d3c9ea083823e65ff61bc47d8b40db6ad03bc0c8e323cbaa6229a43115b098"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"CikaPL4eXatBbz22xWPQx3bPVnjmEbFh5Id2OKev99QmsjtOvL7y+OV4nWHuMEOPd8K3Ll6DhppF4zJjBYvWCg==","signed_message":"bundle_sha256_bytes","signed_at":"2026-08-07T00:28:10.451462Z","bundle_sha256":"438a27b51a68331d4a20628247856beaa1e55f27f1b6348daee2c246dc78464d"}}