{"paper":{"title":"Escaping Helium and a Highly Muted Spectrum Suggest a Metal-Enriched Atmosphere on Sub-Neptune GJ3090b from JWST Transit Spectroscopy","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.EP","authors_text":"Amy J. Louca, Anna Gagnebin, Bj\\\"orn Benneke, Caroline Piaulet-Ghorayeb, Charles Cadieux, Cyril Gapp, Duncan Christie, Eshan Raul, Eva-Maria Ahrer, Hamish Innes, Heather A. Knutson, Hilke E. Schlichting, Jonathan J. Fortney, Joshua E. Krissansen-Totton, Lindsey S. Wiser, Lorena Acuna, Louis-Philippe Coulombe, Luis Welbanks, Michael Radica, Morgan Saidel, Pierre-Alexis Roy, Raymond T. Pierrehumbert, Ren\\'e Doyon, Romain Allart, Ryan Cloutier, Ryan J. MacDonald, Thaddeus D. Komacek, Thomas G. Beatty, Thomas M. Evans-Soma, Yamila Miguel","submitted_at":"2025-04-29T04:48:16Z","abstract_excerpt":"Sub-Neptunes, the most common planet type, remain poorly understood. Their atmospheres are expected to be diverse, but their compositions are challenging to determine, even with JWST. Here, we present the first JWST spectroscopic study of the warm sub-Neptune GJ3090b (2.13R$_\\oplus$, Teq~700 K) which orbits an M2V star, making it a favourable target for atmosphere characterization. We observed four transits of GJ3090b; two each using JWST NIRISS/SOSS and NIRSpec/G395H, yielding wavelength coverage from 0.6-5.2 $\\mu$m. We detect the signature of the 10833 \\r{A} metastable Helium triplet at a st"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2504.20428","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/2504.20428/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"}