{"record_type":"pith_number_record","schema_url":"https://pith.science/schemas/pith-number/v1.json","pith_number":"pith:2017:S2ZPD2CML6S5R46NMOF2NSLU6X","short_pith_number":"pith:S2ZPD2CM","schema_version":"1.0","canonical_sha256":"96b2f1e84c5fa5d8f3cd638ba6c974f5e1c0a3941ac4834531954a4f98e2f136","source":{"kind":"arxiv","id":"1710.03876","version":1},"attestation_state":"computed","paper":{"title":"CO-Driven Activity in Comet C/2017 K2 (PANSTARRS)","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.EP","authors_text":"Eugene Magnier, Eva Lilly, Haynes Stephens, Heather Flewelling, Jacqueline V. Keane, James Bauer, Jan T. Kleyna, Karen J. Meech, Kenneth C. Chambers, Larry Denneau, Marco Micheli, Olivier Hainaut, Richard Wainscoat, Robert Jedicke, Robert Weryk","submitted_at":"2017-10-11T01:35:16Z","abstract_excerpt":"Comet C/2017 K2 (PANSTARRS) was discovered by the Pan-STARRS1 (PS1) Survey on 2017 May 21 at a distance 16.09 au from the Sun, the second most distant discovery of an active comet. Pre-discovery images in the PS1 archive back to 2014 and additional deep CFHT images between 2013 May 10-13 showed the comet to be active at 23.75 au. We derive an upper limit to the nucleus radius of $R_N$=80 km, assuming a 4\\% albedo. The spectral reflectivity of the comet surface is similar to \"fresh\" regions seen on comet 67P/Churyumov-Gerasimenko using the $Rosetta$ OSIRIS camera. Pre-discovery photometry combi"},"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":"1710.03876","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.EP","submitted_at":"2017-10-11T01:35:16Z","cross_cats_sorted":[],"title_canon_sha256":"7d76ca03c5be1830a181a864770b1e63c5b0c22d747e3afb666627151af659d4","abstract_canon_sha256":"b1068b3139340b7a04177a88909a3feac91cc9b288f61fb6da8739a74b6649b0"},"schema_version":"1.0"},"receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T00:31:39.590704Z","signature_b64":"ICQr+5n+mqPQ32c93u75bQwyNxn63xyPTMs+LxbwdS2OTXl1jjfM51qgIRFBVZCExGWMiLirXS0P7wqG10IgDQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"96b2f1e84c5fa5d8f3cd638ba6c974f5e1c0a3941ac4834531954a4f98e2f136","last_reissued_at":"2026-05-18T00:31:39.590256Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T00:31:39.590256Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"graph_snapshot":{"paper":{"title":"CO-Driven Activity in Comet C/2017 K2 (PANSTARRS)","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.EP","authors_text":"Eugene Magnier, Eva Lilly, Haynes Stephens, Heather Flewelling, Jacqueline V. Keane, James Bauer, Jan T. Kleyna, Karen J. Meech, Kenneth C. Chambers, Larry Denneau, Marco Micheli, Olivier Hainaut, Richard Wainscoat, Robert Jedicke, Robert Weryk","submitted_at":"2017-10-11T01:35:16Z","abstract_excerpt":"Comet C/2017 K2 (PANSTARRS) was discovered by the Pan-STARRS1 (PS1) Survey on 2017 May 21 at a distance 16.09 au from the Sun, the second most distant discovery of an active comet. Pre-discovery images in the PS1 archive back to 2014 and additional deep CFHT images between 2013 May 10-13 showed the comet to be active at 23.75 au. We derive an upper limit to the nucleus radius of $R_N$=80 km, assuming a 4\\% albedo. The spectral reflectivity of the comet surface is similar to \"fresh\" regions seen on comet 67P/Churyumov-Gerasimenko using the $Rosetta$ OSIRIS camera. Pre-discovery photometry combi"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1710.03876","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":""},"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":"1710.03876","created_at":"2026-05-18T00:31:39.590330+00:00"},{"alias_kind":"arxiv_version","alias_value":"1710.03876v1","created_at":"2026-05-18T00:31:39.590330+00:00"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1710.03876","created_at":"2026-05-18T00:31:39.590330+00:00"},{"alias_kind":"pith_short_12","alias_value":"S2ZPD2CML6S5","created_at":"2026-05-18T12:31:43.269735+00:00"},{"alias_kind":"pith_short_16","alias_value":"S2ZPD2CML6S5R46N","created_at":"2026-05-18T12:31:43.269735+00:00"},{"alias_kind":"pith_short_8","alias_value":"S2ZPD2CM","created_at":"2026-05-18T12:31:43.269735+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/S2ZPD2CML6S5R46NMOF2NSLU6X","json":"https://pith.science/pith/S2ZPD2CML6S5R46NMOF2NSLU6X.json","graph_json":"https://pith.science/api/pith-number/S2ZPD2CML6S5R46NMOF2NSLU6X/graph.json","events_json":"https://pith.science/api/pith-number/S2ZPD2CML6S5R46NMOF2NSLU6X/events.json","paper":"https://pith.science/paper/S2ZPD2CM"},"agent_actions":{"view_html":"https://pith.science/pith/S2ZPD2CML6S5R46NMOF2NSLU6X","download_json":"https://pith.science/pith/S2ZPD2CML6S5R46NMOF2NSLU6X.json","view_paper":"https://pith.science/paper/S2ZPD2CM","resolve_alias":"https://pith.science/api/pith-number/resolve?arxiv=1710.03876&json=true","fetch_graph":"https://pith.science/api/pith-number/S2ZPD2CML6S5R46NMOF2NSLU6X/graph.json","fetch_events":"https://pith.science/api/pith-number/S2ZPD2CML6S5R46NMOF2NSLU6X/events.json","actions":{"anchor_timestamp":"https://pith.science/pith/S2ZPD2CML6S5R46NMOF2NSLU6X/action/timestamp_anchor","attest_storage":"https://pith.science/pith/S2ZPD2CML6S5R46NMOF2NSLU6X/action/storage_attestation","attest_author":"https://pith.science/pith/S2ZPD2CML6S5R46NMOF2NSLU6X/action/author_attestation","sign_citation":"https://pith.science/pith/S2ZPD2CML6S5R46NMOF2NSLU6X/action/citation_signature","submit_replication":"https://pith.science/pith/S2ZPD2CML6S5R46NMOF2NSLU6X/action/replication_record"}},"created_at":"2026-05-18T00:31:39.590330+00:00","updated_at":"2026-05-18T00:31:39.590330+00:00"}