An international team of researchers have used the power of ESO’s Very Large Telescope to study the atmosphere of exoplanet WASP-19b in such detail that astronomers have been able to detect titanium oxide. This capability tells us that soon we could be able to study the atmosphere of habitable planets.
But, as reported in Nature, WASP-19b is far from habitable. The exoplanet is an infernal world with a temperature around 2,000°C (3,600°F). The team was able to detect traces of titanium oxide, water, and sodium as well as a highly scattering haze layer.
“Detecting such molecules is, however, no simple feat,” Elyar Sedaghati, a fellow at ESO, said in a statement. “Not only do we need data of exceptional quality, but we also need to perform a sophisticated analysis. We used an algorithm that explores many millions of spectra spanning a wide range of chemical compositions, temperatures, and cloud or haze properties in order to draw our conclusions.”
The planet is the same size as Jupiter, but it’s so close to its star, located 815 light-years away, that it orbits in just 19 hours. Being so close allowed astronomers to use the light of the star as it passed through WASP-19b's atmosphere to study it.
This is not the first exoplanet that has been detected to have titanium oxide. WASP-121b also has such an element and it acts similar to how ozone behaves on Earth, helping to create a stratosphere – a region of the atmosphere that is hotter than the lower layers.
“The presence of titanium oxide in the atmosphere of WASP-19b can have substantial effects on the atmospheric temperature structure and circulation,” team member Ryan MacDonald, from Cambridge University, explained.
“To be able to examine exoplanets at this level of detail is promising and very exciting,” added Nikku Madhusudhan, also of Cambridge.
WASP-121b titanium oxide was discovered with a different technique compared to WASP-19b – and this is where the excitement comes from. This approach allows for better data on planetary atmospheres and that, in turn, means better characterization of planetary models.
It’s not an easy task. It took a year of observations to work out the atmosphere of a single planet, but as we get better, we will learn a lot more, a lot faster.
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