Overview

• The Science study reports PH3 at 0.100 ± 0.009 ppm in Wolf 1130C, the first clear brown-dwarf detection of the molecule.
• JWST’s NIRSpec captured multiple phosphine absorption lines, with abundances quantified via atmospheric retrievals led by Eileen Gonzales.
• The result contrasts with prior brown-dwarf and exoplanet observations that found phosphine far below expectations or not at all.
• Authors suggest low metallicity, possible phosphorus supplied by a white-dwarf companion’s past novae, or strong vertical mixing as testable explanations.
• Scientists caution against treating phosphine as a standalone biosignature and call for further JWST observations and improved phosphorus-chemistry models.