Escaping Helium and a Highly Muted Spectrum Suggest a Metal-Enriched Atmosphere on Sub-Neptune GJ3090b from JWST Transit Spectroscopy

Eva-Maria Ahrer, Michael Radica, Caroline Piaulet-Ghorayeb +27

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 JW…