Observations of the highly unusual – sometimes referred to as "forbidden" – exoplanet TOI-5205 b by JWST suggest that the giant planet's atmosphere contains fewer heavy elements than its host star. These findings have implications for our understanding of how giant planets form in a star's early life. The results, published this week in The Astronomical Journal, represent the collaborative work of an international team of astronomers led by Caleb Cañas of NASA Goddard Space Flight Center and including Shubham Kanodia of Carnegie Science. TOI 5205 b is a Jupiter-sized planet orbiting a star that is itself about four times Jupiter's size and about 40 percent of the Sun's mass. When it passes in front of its star – a phenomenon astronomers call a "transit" – the planet blocks about six percent of its light. By observing this...