What can an extremely hot Neptune-sized exoplanet teach scientists about exoplanetary weather? This is what a recent study published Nature Astronomy hopes to address as an international team of researchers investigated the extreme weather patterns on the “ultra-hot Neptune” exoplanet, LTT 9779 b, which is tidally locked to its star and orbits so close to its star that it’s causing unique cloud and weather patterns. This study has the potential to help scientists better understand the formation and evolution of ultra-hot exoplanets and how these worlds remain intact.
“This planet provides a unique laboratory to understand how clouds and the transport of heat interact in the atmospheres of highly irradiated worlds,” said Louis-Philippe Coulombe, who is a PhD student at the University of Montreal’s (UdeM) Trottier Institute for Research on Exoplanets (IREx) and lead author of the study.
Located approximately 262 light-years from Earth, LTT 9779 b orbits its star in only 0.8 days, or just over 19 hours, meaning its tidally locked orbit results in dayside temperatures of just below 2,000 degrees Celsius (3,600 degrees Fahrenheit) while its nightside temperatures are just over 1,000 degrees Celsius (1,800 degrees Fahrenheit).
Using NASA’s powerful James Webb Space Telescope (JWST), the researchers were able to ascertain intriguing weather patterns at the dayside-nightside boundary, also called the terminator. As powerful winds travel around LTT 9779 b, the western side of the dayside experiences cloudy conditions while the eastern side has cloud-free conditions, the latter resulting from the clouds evaporating from the intense heat.
Artist’s illustration of LTT 9779 b, whose dayside is cloud-free from the intense temperatures since the exoplanet is tidally locked with its star, and a cloudy nightside due to much cooler temperatures. (Credit: Benoit Gougeon, Université de Montréal)
"By modeling LTT 9779 b’s atmosphere in detail, we’re starting to unlock the processes driving its alien weather patterns," said Dr. Björn Benneke, who is a UdeM professor of astronomy and a co-author on the study.
Going forward, this study demonstrates the incredible power of JWST being able to reveal intricate and unique details about exoplanets, teaching scientists new and exciting exoplanetary characteristics about worlds beyond Earth.
What new discoveries about ultra-hot exoplanets will researchers make in the coming years and decades? Only time will tell, and this is why we science!
As always, keep doing science & keep looking up!
Sources: Nature Astronomy, NASA, EurekAlert!