{"paper":{"title":"The NUV transit of XO-3 b","license":"http://creativecommons.org/licenses/by/4.0/","headline":"NUV transit of hot Jupiter XO-3b is 30-70% deeper than optical and arrives 22 minutes late.","cross_cats":[],"primary_cat":"astro-ph.EP","authors_text":"Akihiko Fukui, George W. King, James T. Sikora, Jiayin Dong, Juliette Becker, Kohei Miyakawa, Lia Corrales, Lisa Dang, Raven Cilley, Robert Frazier, Teruyuki Hirano","submitted_at":"2026-05-06T16:02:32Z","abstract_excerpt":"Near-UV (NUV) measurements of exoplanet transits offer a means to probe atmospheric escape, cloud formation, and planetary magnetic fields. We examine a 2024 XMM-Newton Optical Monitor NUV observation of the transit of XO-3~b, a massive hot Jupiter on an eccentric orbit with a previously observed abnormally large NUV-absorbing atmosphere. We analyze this NUV data jointly with a concurrent ground-based optical observation and all TESS transit observations, and find a NUV transit depth of $R_{p,NUV}/R_{\\star} = 0.1371^{+0.016}_{-0.019}$, which is 30-70% deeper than the optical transit. Although "},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"We find a NUV transit depth of Rp,NUV/R⋆ = 0.1371+0.016−0.019, which is 30-70% deeper than the optical transit. The transit center in the NUV is 22+13−11 minutes late compared to the optical ephemeris.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"That the observed NUV depth increase and late timing offset arise from atmospheric or bow-shock effects, given that the derived mass-loss rate is extremely small (~10^4 g/s) and the analytic magnetic model predicts an early rather than late transit.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"XO-3 b exhibits a 30-70% deeper NUV transit depth of 0.1371 and a 22-minute late center relative to the optical ephemeris, with an extremely low estimated mass-loss rate and a bow-shock model that predicts the opposite timing direction.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"NUV transit of hot Jupiter XO-3b is 30-70% deeper than optical and arrives 22 minutes late.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"46b6cc07e37b7a236017839ee44ea0f5a728904799abebc90844eed93b981c13"},"source":{"id":"2605.05068","kind":"arxiv","version":2},"verdict":{"id":"c96e2fea-1c17-4fc4-8dfa-b79f6a4ccd14","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-08T15:51:05.092287Z","strongest_claim":"We find a NUV transit depth of Rp,NUV/R⋆ = 0.1371+0.016−0.019, which is 30-70% deeper than the optical transit. The transit center in the NUV is 22+13−11 minutes late compared to the optical ephemeris.","one_line_summary":"XO-3 b exhibits a 30-70% deeper NUV transit depth of 0.1371 and a 22-minute late center relative to the optical ephemeris, with an extremely low estimated mass-loss rate and a bow-shock model that predicts the opposite timing direction.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"That the observed NUV depth increase and late timing offset arise from atmospheric or bow-shock effects, given that the derived mass-loss rate is extremely small (~10^4 g/s) and the analytic magnetic model predicts an early rather than late transit.","pith_extraction_headline":"NUV transit of hot Jupiter XO-3b is 30-70% deeper than optical and arrives 22 minutes late."},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2605.05068/integrity.json","findings":[],"available":true,"detectors_run":[{"name":"ai_meta_artifact","ran_at":"2026-05-20T10:38:01.598527Z","status":"completed","version":"1.0.0","findings_count":0},{"name":"doi_title_agreement","ran_at":"2026-05-19T21:31:19.681990Z","status":"completed","version":"1.0.0","findings_count":0},{"name":"doi_compliance","ran_at":"2026-05-19T13:52:10.004804Z","status":"completed","version":"1.0.0","findings_count":0}],"snapshot_sha256":"da302149ca2d787ac4bd3de1c5e9dae832fcb8a5620c2ade8c3904cedcfa63ef"},"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"}