About 322 light-years from Earth, an extreme planet called WASP-189b orbits one of the hottest stars in the universe, HD 133112.
WASP-189b is 20 times closer to its star than we are to the sun, and its daytime temperature reaches 5,792 degrees Fahrenheit (3,200 degrees Celsius).
The scorching exoplanet also consists of gas and is regarding 1.5 times the size of Jupiter, meaning that it can accommodate 1,950 Earth-sized planets inside it.
Although completely uninhabitable (at least as we understand it), the exoplanet WASP-189b is the first in which scientists have been able to explore distinct layers of its atmosphere, each with its own chemical compositions and properties.
Since its discovery in 2018, scientists very understandably believe that WASP-189b is unlike any other celestial body in our system. But in a paper published in Nature Astronomy, a team of scientists has found a way to connect Earth to its distant cosmic relative, suggesting that the atmosphere of one of the most extreme planets known might also have distinct layers, albeit with very different characteristics, like our own.
“In the past, astronomers often assumed that the atmospheres of exoplanets existed as a uniform layer and attempted to understand it as such,” Jens Hoygmakers, an astrophysicist at Lund University and co-author of the study, said in a statement.
However, when analyzing WASP-189b by measuring starlight passing through the atmosphere of an extremely hot exoplanet, using the HARPS spectrometer at La Silla Observatory in Chile, Huygmakers and colleagues found a unique chemical signature to shake our knowledge of planetary atmospheres.
He noted that the atmosphere of a distant celestial body may contain layers like those of the Earth.
“Gas in the planet’s atmosphere absorb some starlight, similar to ozone, which absorbs some sunlight in Earth’s atmosphere, thus leaving its distinctive fingerprints,” explained Bibiana Prinuth, an astrophysicist at Lund University and lead author of the study.
During preparation, WASP-189b released signals of iron, chromium, vanadium, magnesium, and manganese. But more importantly, says Brinot, “In our analysis, we saw that the fingerprints of different gases changed little compared to our predictions. We believe that strong winds and other processes might generate these changes.”
These modifications varied across the range of detected elements, similar to the way that water vapor and ozone on Earth are affected differently by natural processes due to the layers of the atmosphere. This hints that there are layers on the WASP-189b as well. The team also discovered titanium oxide residues in WASP-189b’s atmospheric shield.
“Titanium oxide absorbs short-wave radiation, such as ultraviolet radiation,” Kevin Heng, an astrophysicist at the University of Bern and a co-author of the study, said in a statement. Its discovery might indicate a layer in WASP-189b’s atmosphere interacts with stellar radiation similarly to how it works. The ozone layer on Earth. So WASP-189b may have its own ozone layer.
“Our results show that even the atmospheres of gas giant planets that have been intensely irradiated have complex three-dimensional structures,” Hoygmakers explained.
