Overview
- The Nature Astronomy study reports a clear JWST detection of hydrogen sulfide in the atmosphere of HR 8799 c.
- The inner three giants in the system are uniformly enriched in heavy elements such as carbon, oxygen and sulfur relative to their star, signaling growth by accreting solids.
- Researchers developed new data-extraction techniques and refined atmospheric models to isolate planetary spectra about 10,000 times fainter than the host star.
- The results extend core accretion to very massive gas giants on wide orbits—five to ten Jupiter masses at roughly 15–70 AU—in the young (~30 Myr), 133 light-year-distant HR 8799 system.
- The team highlights that this chemistry-based approach can be applied to other systems to refine planet-formation theories and probe the planet–brown-dwarf boundary.