{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2019:DSYHUHVHDATMPIJMGYZ4LPPHV2","short_pith_number":"pith:DSYHUHVH","canonical_record":{"source":{"id":"1903.01987","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.SR","submitted_at":"2019-03-05T18:59:32Z","cross_cats_sorted":[],"title_canon_sha256":"2ed74d0bcbdc2deeff6e5403910245262008880109ed6616c0537cb55191efa3","abstract_canon_sha256":"24bb1a97291fd6ee3a7a444d3115a099b69e9b20ffce5aca4bfe432f7b7d0914"},"schema_version":"1.0"},"canonical_sha256":"1cb07a1ea71826c7a12c3633c5bde7ae831555bf12542256f8a8192fc93e45b4","source":{"kind":"arxiv","id":"1903.01987","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1903.01987","created_at":"2026-05-17T23:49:01Z"},{"alias_kind":"arxiv_version","alias_value":"1903.01987v1","created_at":"2026-05-17T23:49:01Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1903.01987","created_at":"2026-05-17T23:49:01Z"},{"alias_kind":"pith_short_12","alias_value":"DSYHUHVHDATM","created_at":"2026-05-18T12:33:15Z"},{"alias_kind":"pith_short_16","alias_value":"DSYHUHVHDATMPIJM","created_at":"2026-05-18T12:33:15Z"},{"alias_kind":"pith_short_8","alias_value":"DSYHUHVH","created_at":"2026-05-18T12:33:15Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2019:DSYHUHVHDATMPIJMGYZ4LPPHV2","target":"record","payload":{"canonical_record":{"source":{"id":"1903.01987","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.SR","submitted_at":"2019-03-05T18:59:32Z","cross_cats_sorted":[],"title_canon_sha256":"2ed74d0bcbdc2deeff6e5403910245262008880109ed6616c0537cb55191efa3","abstract_canon_sha256":"24bb1a97291fd6ee3a7a444d3115a099b69e9b20ffce5aca4bfe432f7b7d0914"},"schema_version":"1.0"},"canonical_sha256":"1cb07a1ea71826c7a12c3633c5bde7ae831555bf12542256f8a8192fc93e45b4","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-17T23:49:01.666288Z","signature_b64":"+2t5o3kXyThw6H8Oyv59sMIf9TKiNvdbFnw317MWs2GKJY1qOgBhySOlzib8ZetVeeSehcAllnJkO8vMd8zDBA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"1cb07a1ea71826c7a12c3633c5bde7ae831555bf12542256f8a8192fc93e45b4","last_reissued_at":"2026-05-17T23:49:01.665883Z","signature_status":"signed_v1","first_computed_at":"2026-05-17T23:49:01.665883Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1903.01987","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":"2026-05-17T23:49:01Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"HwqQLyrHc0RQQaTl4i9p4IYBtLQn1x9YNdhQcRlaXwEA0N4sFFMlXkokDNUCp73BZmT3fxI1Od4IZ2eNQeepCA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-06T19:46:53.612598Z"},"content_sha256":"ba59e88d595d36eb2507e1f3c4d0a4a688027409f58c671f67e73202a337c5a7","schema_version":"1.0","event_id":"sha256:ba59e88d595d36eb2507e1f3c4d0a4a688027409f58c671f67e73202a337c5a7"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2019:DSYHUHVHDATMPIJMGYZ4LPPHV2","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Multi-epoch Ultraviolet HST Observations of Accreting Low-mass Stars","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.SR","authors_text":"Catherine Espaillat, Connor Robinson","submitted_at":"2019-03-05T18:59:32Z","abstract_excerpt":"Variability is a defining characteristic of young low-mass stars that are still accreting material from their primordial protoplanetary disk. Here we present the largest \\textit{HST} variability study of Classical T Tauri stars (CTTS) to date. For 5 of these objects, we obtained a total of 25 spectra with the Space Telescope Imaging Spectrograph (STIS). Mass accretion rates and the fraction of the star covered by accretion columns (i.e., filling factors) were inferred using 1D NLTE physical models whose parameters were fit within a Bayesian framework. On week long timescales, typical changes i"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1903.01987","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"},"verdict_id":null},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-17T23:49:01Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"SG6zXS466Nu4SPOg5UmGX5UDMNo1xbt9fRqqxpBtwJ03GDsLZ0WcY+Dhxhea+3iQxdvNNoEtIG7Sq8NtBatQCw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-06T19:46:53.613248Z"},"content_sha256":"1686a7a987c321496010d14a37ec86408fadc65ecaf2fdc3f1085ee7dc1da17b","schema_version":"1.0","event_id":"sha256:1686a7a987c321496010d14a37ec86408fadc65ecaf2fdc3f1085ee7dc1da17b"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/DSYHUHVHDATMPIJMGYZ4LPPHV2/bundle.json","state_url":"https://pith.science/pith/DSYHUHVHDATMPIJMGYZ4LPPHV2/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/DSYHUHVHDATMPIJMGYZ4LPPHV2/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":"2026-06-06T19:46:53Z","links":{"resolver":"https://pith.science/pith/DSYHUHVHDATMPIJMGYZ4LPPHV2","bundle":"https://pith.science/pith/DSYHUHVHDATMPIJMGYZ4LPPHV2/bundle.json","state":"https://pith.science/pith/DSYHUHVHDATMPIJMGYZ4LPPHV2/state.json","well_known_bundle":"https://pith.science/.well-known/pith/DSYHUHVHDATMPIJMGYZ4LPPHV2/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2019:DSYHUHVHDATMPIJMGYZ4LPPHV2","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":"24bb1a97291fd6ee3a7a444d3115a099b69e9b20ffce5aca4bfe432f7b7d0914","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.SR","submitted_at":"2019-03-05T18:59:32Z","title_canon_sha256":"2ed74d0bcbdc2deeff6e5403910245262008880109ed6616c0537cb55191efa3"},"schema_version":"1.0","source":{"id":"1903.01987","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1903.01987","created_at":"2026-05-17T23:49:01Z"},{"alias_kind":"arxiv_version","alias_value":"1903.01987v1","created_at":"2026-05-17T23:49:01Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1903.01987","created_at":"2026-05-17T23:49:01Z"},{"alias_kind":"pith_short_12","alias_value":"DSYHUHVHDATM","created_at":"2026-05-18T12:33:15Z"},{"alias_kind":"pith_short_16","alias_value":"DSYHUHVHDATMPIJM","created_at":"2026-05-18T12:33:15Z"},{"alias_kind":"pith_short_8","alias_value":"DSYHUHVH","created_at":"2026-05-18T12:33:15Z"}],"graph_snapshots":[{"event_id":"sha256:1686a7a987c321496010d14a37ec86408fadc65ecaf2fdc3f1085ee7dc1da17b","target":"graph","created_at":"2026-05-17T23:49:01Z","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"},"paper":{"abstract_excerpt":"Variability is a defining characteristic of young low-mass stars that are still accreting material from their primordial protoplanetary disk. Here we present the largest \\textit{HST} variability study of Classical T Tauri stars (CTTS) to date. For 5 of these objects, we obtained a total of 25 spectra with the Space Telescope Imaging Spectrograph (STIS). Mass accretion rates and the fraction of the star covered by accretion columns (i.e., filling factors) were inferred using 1D NLTE physical models whose parameters were fit within a Bayesian framework. On week long timescales, typical changes i","authors_text":"Catherine Espaillat, Connor Robinson","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.SR","submitted_at":"2019-03-05T18:59:32Z","title":"Multi-epoch Ultraviolet HST Observations of Accreting Low-mass Stars"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1903.01987","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:ba59e88d595d36eb2507e1f3c4d0a4a688027409f58c671f67e73202a337c5a7","target":"record","created_at":"2026-05-17T23:49:01Z","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":"24bb1a97291fd6ee3a7a444d3115a099b69e9b20ffce5aca4bfe432f7b7d0914","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.SR","submitted_at":"2019-03-05T18:59:32Z","title_canon_sha256":"2ed74d0bcbdc2deeff6e5403910245262008880109ed6616c0537cb55191efa3"},"schema_version":"1.0","source":{"id":"1903.01987","kind":"arxiv","version":1}},"canonical_sha256":"1cb07a1ea71826c7a12c3633c5bde7ae831555bf12542256f8a8192fc93e45b4","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"1cb07a1ea71826c7a12c3633c5bde7ae831555bf12542256f8a8192fc93e45b4","first_computed_at":"2026-05-17T23:49:01.665883Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-17T23:49:01.665883Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"+2t5o3kXyThw6H8Oyv59sMIf9TKiNvdbFnw317MWs2GKJY1qOgBhySOlzib8ZetVeeSehcAllnJkO8vMd8zDBA==","signature_status":"signed_v1","signed_at":"2026-05-17T23:49:01.666288Z","signed_message":"canonical_sha256_bytes"},"source_id":"1903.01987","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:ba59e88d595d36eb2507e1f3c4d0a4a688027409f58c671f67e73202a337c5a7","sha256:1686a7a987c321496010d14a37ec86408fadc65ecaf2fdc3f1085ee7dc1da17b"],"state_sha256":"17f76a5d2d1f1e9d3ebe1f709c214af4bf450400359c0464c9acb95d9ebe4764"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"zYUu2MuJ56BaNZ7hZ05IcLW3qZGJB40A18jHsUuIJiCiFmTev1wqf8NCaUAH0T9RTFFqgLYZDVxvX8Xx4hI3Dw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-06T19:46:53.616530Z","bundle_sha256":"afab7bda9eebd7f735115c51d9837d105cb9722ab77b2ad28fdd039f68bedba6"}}