Overview
- An Oxford‑led team reports in Nature Astronomy that L 98‑59 d, about 35 light‑years away, has a mean density far below Earth’s despite a radius near 1.6 Earths.
- JWST observations indicate a hydrogen‑bearing atmosphere containing hydrogen sulfide and sulfur dioxide.
- Modeling proposes a deep, long‑lived magma ocean that stores and releases sulfur, suggesting a possible new class of small planets.
- Simulations favor formation with unusually high water and sulfur followed by stellar radiation stripping lighter gases.
- The authors note that conclusions depend on spectral interpretation and interior models, with the presence of a solid crust and tidal‑locking effects still uncertain.