How do ultra-hot Jupiters form and evolve? This is what a recent study published in Nature Astronomy hopes to address as a team of researchers investigated the origins of WASP-121b, which is an ultra-hot Jupiter that orbits its F-type star (larger than our Sun) in only 30.5 hours. For context, the planet Mercury orbits the Sun in 88 days. Therefore, this study has the potential to help scientists better understand the formation and evolution of exoplanets that challenge the planets of our solar system and where we could potentially find life as we know it.
For the study, the researchers used NASA’s James Webb Space Telescope to observe WASP-121b, which is located approximately 880 light-years from Earth and experiences temperatures greater than 3,000 degrees Celsius (5,400 degrees Fahrenheit) on its dayside and 1,500 degrees Celsius (2,700 degrees Fahrenheit) on its night side since it’s tidally locked with its star. The goal of the study was to ascertain how the compounds within WASP-121b’s atmosphere evaporated from its searing temperatures, which could provide clues regarding where in the protoplanetary disk it initially formed.
In the end, the researchers determined that WASP-121b likely formed at a distance much farther out from its current orbit where water is frozen but certain gases like methane are still in their gaseous form. This distance is comparable to existing between the orbits of Jupiter and Uranus in our own solar system, which then begs the question as to how WASP-121b ended up orbiting so close to its star?
The researchers concluded that WASP-121b gathered most of its gas and dust as it migrated inwards, resulting in lopsided ratios of carbon-hydrogen, oxygen-hydrogen, and carbon-oxygen. Despite its searing temperatures, the team was able to ascertain the traverse of compounds from the dayside to the night side and backtrack how this came to be today.
What new discoveries about ultra-hot Jupiters 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, EurekAlert!
Featured Image: Artist’s illustration of WASP-121b forming within its protoplanetary disk. (Credit: T. Müller (MPIA/HdA))
