James Webb Telescope Studies Rare Temperate Gas Giant TOI-199b

Rare TOI-199b Planet Studied

Astronomers have found new details about TOI-199b, a rare Jupiter-sized planet located more than 330 light-years away from Earth. The planet has drawn attention because its atmospheric temperature is estimated to be around 175 degrees Fahrenheit, making it significantly cooler than most giant exoplanets discovered near distant stars. TOI-199b completes one orbit around its parent star every 100 days and falls into the rare category of temperate gas giants.

JWST Detects Methane

Using NASA’s James Webb Space Telescope, scientists studied the planet’s atmosphere through transmission spectroscopy. During the planet’s transit in front of its star, JWST analysed starlight passing through the atmosphere and identified gases based on how they absorbed light. The observations showed strong signs of methane, along with possible traces of ammonia and carbon dioxide.

Why This Discovery Matters

TOI-199b is not suitable for human life and is not a true Earth 2.0. However, its mild temperature and complex atmosphere make it important for understanding how planets form and evolve. Scientists say the findings can improve models of planetary atmospheres across the galaxy.