Webb finds ammonia and unexpectedly cold atmosphere on exoplanet HATS-6 b

The James Webb Space Telescope has revealed that exoplanet HATS-6 b, already difficult to explain, has an atmosphere nearly 200 K colder than expected and contains ammonia, adding new mysteries to its origin. HATS-6 b is roughly Jupiter's size but only a third of its mass, orbiting a small red dwarf every 3.3 days. Webb detected water, methane, carbon dioxide, and ammonia, a rare finding, with the planet's temperature measured at about 514 K versus the predicted 712 K. The cold temperature may be due to highly reflective clouds, with a possible Bond albedo near 0.71, similar to Venus. Additionally, the atmosphere's metallicity is far lower than the planet's estimated bulk composition, suggesting heavy elements remain hidden in deeper layers.