{"paper":{"title":"An optical transmission spectrum for the ultra-hot Jupiter WASP-121b measured with the Hubble Space Telescope","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.EP","authors_text":"Alain Lecavelier des Etangs, Antonio Garcia Munoz, Benjamin Drummond, David Ehrenreich, David K. Sing, Eric Hebrard, Gilda E. Ballester, Gregory W. Henry, Hannah R. Wakeford, Jayesh Goyal, Joanna K. Barstow, Jorge Sanz-Forcada, Kevin Zahnle, Lars A. Buchhave, Lotfi Ben-Jaffel, Mark S. Marley, Mercedes Lopez-Morales, Michael H. Williamson, Munazza K. Alam, Nikolay Nikolov, Nikole K. Lewis, Panayotis Lavvas, Pascal Tremblin, Sarah D. Blumenthal, Thomas M. Evans, Tiffany Kataria, Vincent Bourrier","submitted_at":"2018-10-25T16:46:23Z","abstract_excerpt":"We present an atmospheric transmission spectrum for the ultra-hot Jupiter WASP-121b, measured using the Space Telescope Imaging Spectrograph (STIS) onboard the Hubble Space Telescope (HST). Across the 0.47-1 micron wavelength range, the data imply an atmospheric opacity comparable to - and in some spectroscopic channels exceeding - that previously measured at near-infrared wavelengths (1.15-1.65 micron). Wavelength-dependent variations in the opacity rule out a gray cloud deck at a confidence level of 3.8-sigma and may instead be explained by VO spectral bands. We find a cloud-free model assum"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1810.10969","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"}