Bright Skies on a Distant Neptune: Discovering Reflective Clouds on LTT 9779b
Astronomers observed the ultra-hot Neptune LTT 9779b using JWST and found that its western dayside is highly reflective due to silicate clouds, while the eastern dayside absorbs more light. The planet’s temperature is 2,260 K on the dayside and below 1,330 K on the nightside. An eastward jet likely moves heat away, allowing clouds to form in cooler regions. These findings improve our understanding of exoplanet atmospheres and cloud formation.
The Hottest Neptunes: Exploring Planet Formation in Metal-Rich Systems
The study explores "Neptune desert" planets—rare, close-orbiting worlds between Neptune and Saturn in size—and finds they orbit metal-rich stars. These planets likely formed from gas giants that lost their outer layers, as their host stars' metallicities resemble those of hot Jupiter hosts. The findings challenge other formation theories, offering new insights into planetary evolution near stars.