{"paper":{"title":"The Rossiter-McLaughlin Effect of the Transiting Exoplanet XO-4b","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.EP","authors_text":"Bun'ei Sato, Joshua N. Winn, Matthew J. Holman, Motohide Tamura, Norio Narita, Roberto Sanchis-Ojeda, Teruyuki Hirano, Wako Aoki","submitted_at":"2010-08-23T12:14:15Z","abstract_excerpt":"We report photometric and radial velocity observations of the XO-4 transiting planetary system, conducted with the FLWO 1.2m telescope and the 8.2m Subaru Telescope. Based on the new light curves, the refined transit ephemeris of XO-4b is $P = 4.1250828 \\pm 0.0000040$ days and $T_c [BJD_TDB] = 2454485.93323 \\pm 0.00039$. We measured the Rossiter-McLaughlin effect of XO-4b and estimated the sky-projected angle between the stellar spin axis and the planetary orbital axis to be $\\lambda = -46.7^{\\circ} ^{+8.1^{\\circ}}_{-6.1^{\\circ}}$. This measurement of $\\lambda$ is less robust than in some othe"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1008.3803","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"}