Free Astronomy Magazine January-February 2023

JANUARY-FEBRUARY 2023 T his illustration shows a night-side view of the exoplanet WASP-76 b. The ultra-hot giant exoplanet has a day side where temperatures climb above 2400 degrees Celsius, high enough to vaporise metals. Strong winds carry iron vapour to the cooler night side where it condenses into iron droplets. To the left of the image, we see the evening border of the ex- oplanet, where it transitions from day to night. [ESO/M. Kornmesser] U sing ESO’s Very Large Telescope, barium has been detected in the atmosphere of two exoplanets. The video summarizes the discovery. [ESO] ement to be at such high altitudes in these exoplanets. “At the moment, we are not sure what the mecha- nisms are,” explains Demangeon. In the study of exoplanet atmos- pheres ultra-hot Jupiters are ex- tremely useful. As Demangeon ex- plains: “Being gaseous and hot, their atmospheres are very ex- tended and are thus easier to ob- serve and study than those of smaller or cooler planets.” Determining the composition of an