Orbiting too close to its host star, the exoplanet WASP-189 b has extremely high temperatures and completes an orbit in just 2.7 days.
Astronomers have analyzed one of the harshest exoplanets known, WASP-189 b, and found that it has a multi-layered atmosphere similar to Earth, as reported by IFL Science on January 29. However, that is where the similarities end. This planet has a mass twice that of Jupiter, with temperatures soaring into the thousands of degrees, making it uninhabitable for humans.
Illustration of exoplanet WASP-189 b orbiting its host star. (Image: ESA)
WASP-189 b is extremely hot due to its proximity to the host star. It orbits its star in just 2.7 days, at a distance of 1/20th that of the Earth-Sun distance. However, this proximity allows scientists to study the atmosphere of WASP-189 b in detail.
According to research published in the journal Nature Astronomy, an international team of experts has identified the presence of iron, chromium, vanadium, magnesium, manganese, and titanium oxide in the atmosphere of this planet.
“We measured the light from the host star passing through the atmosphere of WASP-189 b. The gases in this planet’s atmosphere absorb some of the starlight, similar to how ozone absorbs certain sunlight in Earth’s atmosphere, leaving behind a characteristic ‘fingerprint.’ With the help of the exoplanet-hunting machine HARPS, we identified the corresponding substances,” said expert Bibiana Prinoth from Lund University, a member of the research team.
Titanium oxide is a particularly interesting discovery, as scientists have previously found this substance in ozone-like layers and some stratosphere-like layers on other exoplanets. However, the new study has also found evidence of additional layers.
“We observed that the ‘fingerprints’ of various gases changed slightly from our predictions. We believe that strong winds and other processes could cause this variation. Each gas’s fingerprint changes in its own way, indicating that they exist in different layers—similar to how the fingerprints of water vapor and ozone on Earth would look different when viewed from afar,” Prinoth explained.
There is still much that scientists do not know about the atmospheres of exoplanets, and even the atmospheres of giant gas planets in our solar system remain very mysterious. The new research contributes to clarifying why exoplanets like WASP-189 b do not have a single-layer atmosphere.
“We believe that to fully understand these planets and other types of planets, including those more Earth-like, we need to study the three-dimensional nature of their atmospheres. This requires innovation in data analysis techniques, computer modeling, and the development of fundamental atmospheric theories,” concluded co-author Kevin Heng.
