Overview
- Researchers using the James Webb Space Telescope report in The Astronomical Journal that TOI‑5205 b’s atmosphere has fewer heavy elements than its own star, the lowest yet measured for a gas giant.
- The spectra from three transits also reveal methane and hydrogen sulfide in the planet’s air.
- Interior models by Simon Muller and Ravit Helled indicate the planet’s bulk is about 100 times richer in heavy elements than the air, which suggests poor mixing between the deep interior and the atmosphere.
- The Jupiter-size world orbits a small red dwarf and blocks about six percent of its light, a deep eclipse that enabled precise readings and required careful correction for starspot effects.
- In astronomy, metallicity means the share of elements heavier than hydrogen and helium, and giants usually show more of these than their stars, so this flipped pattern is driving new GEMS follow-up to test planet-formation ideas.