{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2021:YGOZ7FGDFLC3KYILO2BZJX3JAI","short_pith_number":"pith:YGOZ7FGD","canonical_record":{"source":{"id":"2104.09843","kind":"arxiv","version":2},"metadata":{"license":"http://creativecommons.org/licenses/by-nc-sa/4.0/","primary_cat":"astro-ph.EP","submitted_at":"2021-04-20T09:12:48Z","cross_cats_sorted":[],"title_canon_sha256":"5de365ce1beae7257092b8c16491fbc9cffcbb389f3001749410601bd8d0c7e9","abstract_canon_sha256":"6024e349715fa9176ffc652464f3291fef48002a1d72f4c83778566fff307f4b"},"schema_version":"1.0"},"canonical_sha256":"c19d9f94c32ac5b5610b768394df6902058e8acfd657d3ead4bb663a73adbefa","source":{"kind":"arxiv","id":"2104.09843","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2104.09843","created_at":"2026-07-05T02:51:24Z"},{"alias_kind":"arxiv_version","alias_value":"2104.09843v2","created_at":"2026-07-05T02:51:24Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2104.09843","created_at":"2026-07-05T02:51:24Z"},{"alias_kind":"pith_short_12","alias_value":"YGOZ7FGDFLC3","created_at":"2026-07-05T02:51:24Z"},{"alias_kind":"pith_short_16","alias_value":"YGOZ7FGDFLC3KYIL","created_at":"2026-07-05T02:51:24Z"},{"alias_kind":"pith_short_8","alias_value":"YGOZ7FGD","created_at":"2026-07-05T02:51:24Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2021:YGOZ7FGDFLC3KYILO2BZJX3JAI","target":"record","payload":{"canonical_record":{"source":{"id":"2104.09843","kind":"arxiv","version":2},"metadata":{"license":"http://creativecommons.org/licenses/by-nc-sa/4.0/","primary_cat":"astro-ph.EP","submitted_at":"2021-04-20T09:12:48Z","cross_cats_sorted":[],"title_canon_sha256":"5de365ce1beae7257092b8c16491fbc9cffcbb389f3001749410601bd8d0c7e9","abstract_canon_sha256":"6024e349715fa9176ffc652464f3291fef48002a1d72f4c83778566fff307f4b"},"schema_version":"1.0"},"canonical_sha256":"c19d9f94c32ac5b5610b768394df6902058e8acfd657d3ead4bb663a73adbefa","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T02:51:24.317666Z","signature_b64":"5VX91jboA9TRrBAKuAdzWstZ5ESSlCQxeA27BxNKfO2ZVLzUQm4kH5nRGVhHtyC1aAgjDzIwujng5PxBGgSqCA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"c19d9f94c32ac5b5610b768394df6902058e8acfd657d3ead4bb663a73adbefa","last_reissued_at":"2026-07-05T02:51:24.317152Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T02:51:24.317152Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2104.09843","source_version":2,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-07-05T02:51:24Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"DQdvzVgD7iPmAlj9GG29ABG+9n+eHltFKkU53v652JJpmacm7THtTBfwOBk09YpoGv38I5uEZEA8H1pszKkPBA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-06T22:20:21.680335Z"},"content_sha256":"b25703e3dfa7be5d5297fac12006235b66e7bc2ce823cefdd56fb0d90dab56cd","schema_version":"1.0","event_id":"sha256:b25703e3dfa7be5d5297fac12006235b66e7bc2ce823cefdd56fb0d90dab56cd"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2021:YGOZ7FGDFLC3KYILO2BZJX3JAI","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"How to identify exoplanet surfaces using atmospheric trace species in hydrogen-dominated atmospheres","license":"http://creativecommons.org/licenses/by-nc-sa/4.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.EP","authors_text":"Jonathan J. Fortney, Julianne I. Moses, Xinting Yu, Xi Zhang","submitted_at":"2021-04-20T09:12:48Z","abstract_excerpt":"Sub-Neptunes (Rp~1.25-4 REarth) remain the most commonly detected exoplanets to date. However, it remains difficult for observations to tell whether these intermediate-sized exoplanets have surfaces and where their surfaces are located. Here we propose that the abundances of trace species in the visible atmospheres of these sub-Neptunes can be used as proxies for determining the existence of surfaces and approximate surface conditions. As an example, we used a state-of-the-art photochemical model to simulate the atmospheric evolution of K2-18b and investigate its final steady-state composition"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2104.09843","kind":"arxiv","version":2},"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/2104.09843/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":"2026-07-05T02:51:24Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"XTWcpz/CMykTvSpdxnISSkumtzEbyS/OkFKmLp9NDQZeB+oS2aOgPcJOYuhI14rPbCvkJtzB6W2iP+D+faegCg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-06T22:20:21.680832Z"},"content_sha256":"7859eae9d497f546bfdb687f92aba7936198aab8b6e290636e644cc940a8a62d","schema_version":"1.0","event_id":"sha256:7859eae9d497f546bfdb687f92aba7936198aab8b6e290636e644cc940a8a62d"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/YGOZ7FGDFLC3KYILO2BZJX3JAI/bundle.json","state_url":"https://pith.science/pith/YGOZ7FGDFLC3KYILO2BZJX3JAI/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/YGOZ7FGDFLC3KYILO2BZJX3JAI/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":"2026-08-06T22:20:21Z","links":{"resolver":"https://pith.science/pith/YGOZ7FGDFLC3KYILO2BZJX3JAI","bundle":"https://pith.science/pith/YGOZ7FGDFLC3KYILO2BZJX3JAI/bundle.json","state":"https://pith.science/pith/YGOZ7FGDFLC3KYILO2BZJX3JAI/state.json","well_known_bundle":"https://pith.science/.well-known/pith/YGOZ7FGDFLC3KYILO2BZJX3JAI/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2021:YGOZ7FGDFLC3KYILO2BZJX3JAI","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":"6024e349715fa9176ffc652464f3291fef48002a1d72f4c83778566fff307f4b","cross_cats_sorted":[],"license":"http://creativecommons.org/licenses/by-nc-sa/4.0/","primary_cat":"astro-ph.EP","submitted_at":"2021-04-20T09:12:48Z","title_canon_sha256":"5de365ce1beae7257092b8c16491fbc9cffcbb389f3001749410601bd8d0c7e9"},"schema_version":"1.0","source":{"id":"2104.09843","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2104.09843","created_at":"2026-07-05T02:51:24Z"},{"alias_kind":"arxiv_version","alias_value":"2104.09843v2","created_at":"2026-07-05T02:51:24Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2104.09843","created_at":"2026-07-05T02:51:24Z"},{"alias_kind":"pith_short_12","alias_value":"YGOZ7FGDFLC3","created_at":"2026-07-05T02:51:24Z"},{"alias_kind":"pith_short_16","alias_value":"YGOZ7FGDFLC3KYIL","created_at":"2026-07-05T02:51:24Z"},{"alias_kind":"pith_short_8","alias_value":"YGOZ7FGD","created_at":"2026-07-05T02:51:24Z"}],"graph_snapshots":[{"event_id":"sha256:7859eae9d497f546bfdb687f92aba7936198aab8b6e290636e644cc940a8a62d","target":"graph","created_at":"2026-07-05T02:51:24Z","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/2104.09843/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"Sub-Neptunes (Rp~1.25-4 REarth) remain the most commonly detected exoplanets to date. However, it remains difficult for observations to tell whether these intermediate-sized exoplanets have surfaces and where their surfaces are located. Here we propose that the abundances of trace species in the visible atmospheres of these sub-Neptunes can be used as proxies for determining the existence of surfaces and approximate surface conditions. As an example, we used a state-of-the-art photochemical model to simulate the atmospheric evolution of K2-18b and investigate its final steady-state composition","authors_text":"Jonathan J. Fortney, Julianne I. Moses, Xinting Yu, Xi Zhang","cross_cats":[],"headline":"","license":"http://creativecommons.org/licenses/by-nc-sa/4.0/","primary_cat":"astro-ph.EP","submitted_at":"2021-04-20T09:12:48Z","title":"How to identify exoplanet surfaces using atmospheric trace species in hydrogen-dominated atmospheres"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2104.09843","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:b25703e3dfa7be5d5297fac12006235b66e7bc2ce823cefdd56fb0d90dab56cd","target":"record","created_at":"2026-07-05T02:51:24Z","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":"6024e349715fa9176ffc652464f3291fef48002a1d72f4c83778566fff307f4b","cross_cats_sorted":[],"license":"http://creativecommons.org/licenses/by-nc-sa/4.0/","primary_cat":"astro-ph.EP","submitted_at":"2021-04-20T09:12:48Z","title_canon_sha256":"5de365ce1beae7257092b8c16491fbc9cffcbb389f3001749410601bd8d0c7e9"},"schema_version":"1.0","source":{"id":"2104.09843","kind":"arxiv","version":2}},"canonical_sha256":"c19d9f94c32ac5b5610b768394df6902058e8acfd657d3ead4bb663a73adbefa","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"c19d9f94c32ac5b5610b768394df6902058e8acfd657d3ead4bb663a73adbefa","first_computed_at":"2026-07-05T02:51:24.317152Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T02:51:24.317152Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"5VX91jboA9TRrBAKuAdzWstZ5ESSlCQxeA27BxNKfO2ZVLzUQm4kH5nRGVhHtyC1aAgjDzIwujng5PxBGgSqCA==","signature_status":"signed_v1","signed_at":"2026-07-05T02:51:24.317666Z","signed_message":"canonical_sha256_bytes"},"source_id":"2104.09843","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:b25703e3dfa7be5d5297fac12006235b66e7bc2ce823cefdd56fb0d90dab56cd","sha256:7859eae9d497f546bfdb687f92aba7936198aab8b6e290636e644cc940a8a62d"],"state_sha256":"56328deb8a1317d667efbb7c97d98c1da6b5eb191b21f79a28ce96837c562c49"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"7G2Kaz7ejcNani7+VrK5Kw2chQmKDwDNYkpc5woYslD20ZFtuYHEJnUG+mhZUdEaJGVSQZJMbY09KvLJEyCaCA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-08-06T22:20:21.684356Z","bundle_sha256":"c72915f4830a92547f408e6f0ccbe6caef9d885cb92708087beff80c644ad2cf"}}