In a groundbreaking discovery, astronomers have detected the heavy element barium in the atmospheres of two extreme exoplanets, WASP-76b and WASP-121b. This finding marks the heaviest element ever found in the atmosphere of a planet orbiting a star other than the sun.
The detection of barium, which has an atomic number of 56, is particularly significant as it provides insights into the extreme environments of these exoplanets. WASP-76b and WASP-121b are classified as “ultra-hot Jupiters,” meaning they are gas giants that orbit their host stars at extremely close distances, with orbital periods of less than 5 days. These extreme conditions lead to very high temperatures, reaching up to 2,400 degrees Celsius (4,350 degrees Fahrenheit) on the dayside of the planets.
The presence of barium in the atmospheres of these exoplanets suggests that the extreme temperatures and pressures on these worlds can lead to the vaporization of even the heaviest elements. Typically, barium is found in the solid or liquid state on Earth, but the extreme conditions of WASP-76b and WASP-121b allow it to be present in a gaseous form, making it detectable in the planetary atmospheres.
This discovery has significant implications for our understanding of exoplanetary atmospheres and the processes that shape their composition. The detection of barium, along with other heavy elements, provides valuable insights into the extreme environments of these exoplanets and the complex chemical and physical processes that occur in their atmospheres.