{"paper":{"title":"Optical Super-orbital Modulation of SMC X-1: Disk Precession and a Revised Pulsar Mass","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.HE","authors_text":"Masafumi Niwano, Michael Fausnaugh, Nobuyuki Kawai","submitted_at":"2026-05-20T15:25:30Z","abstract_excerpt":"The observational determination of the lower limit of neutron star masses is crucial for the physics of core-collapse supernovae. In this light, SMC X-1 is an important object because of its estimated pulsar mass lying near or potentially below the theoretical lower limit. SMC X-1 exhibits a double peaked optical orbital light curve due to the tidal distortion of the donor star, and analysis of this allows us to constrain the binary parameters. In this study, we analyzed optical and X-ray light curves of SMC X-1 obtained by Transiting Exoplanet Survey Satellite and Monitor of All-sky X-ray Ima"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2605.21294","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/2605.21294/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"}