"The discovery challenges our understanding of how winds and chemistry work on these hot planets and reveals a large gap between what current models predict and what we actually observe on more varied exoplanets", says Bibiana Prinoth, astrophysicist at Lund University, in a press release.
Researchers in Lund, among others, have made the observations with the European Southern Observatory's telescope in Chile.
Wasp-121 b rotates very close to and in sync with its star. This means that one side always faces the star and becomes extremely hot, around 2,500 degrees, while the other side remains significantly cooler.
A mystery
The temperature difference and how heat is transported in this extreme environment has until now been a mystery.
"We discovered that a jet stream transports material around the planet's equator, while a separate wind at lower heights in the atmosphere transports gas from the hot day side to the cool night side. This climate has never been seen on any planet before and challenges current theories on how atmospheres work on extreme planets", says Bibiana Prinoth.
For the first time, researchers were also able to detect titanium in the exoplanet's atmosphere.
A new giant telescope
Overall, the discoveries provide a better understanding of how atmospheres work. The work helps researchers prepare for studying Earth-like planets with the new giant telescope – Extremely Large Telescope – which is expected to be operational in Chile by the end of the decade.
"Next-generation telescopes will give us incredible insights into the chemistry and dynamics of distant worlds", says Bibiana Prinoth.
The observations are published in two studies in Nature and Astronomy & Astrophysics.
More than 5,800 exoplanets, i.e. planets orbiting other stars than our sun, have been discovered since the 1990s.
Wasp-121 b is located about 900 light-years from Earth and is one of the more extreme examples.
It is slightly larger than our solar system's largest planet Jupiter and orbits very close to its star.
The planet rotates in sync with the star, just like our moon rotates in sync with Earth. This means that one side always faces the star and becomes extremely hot, around 2,500 degrees, while the other side remains significantly cooler.
Source: Lund University
