Barium found in exoplanet atmosphere

Using the ESPRESSO spectrograph mounted on the ESO’s Very Large Telescope (VLT), astronomers registered in the atmosphere of the exoplanet the heaviest of all elements found there so far. It’s about barium. It was found at high altitudes in the atmospheres of the gas giants WASP-76 b and WASP-121 b.

Ultra-hot Jupiter in the artist’s image. Source: ESO/M. Kornmesser

WASP-76 b and WASP-121 b are classified as ultra-hot Jupiters. At similar sizes to Jupiter, their atmospheres are heated to extremely high temperatures exceeding 1000 °C. This is due to their proximity to their mother stars. The orbital period of such worlds is one or two Earth days.

Such extreme conditions in the atmospheres of ultra-hot Jupiters lead to a number of very exotic features. For example, on the exoplanet WASP-76 b, there are iron rains.

But even knowing about such oddities, scientists were surprised when they found barium in the upper layers of the atmospheres WASP-76 b and WASP-121 b, which is 2.5 times heavier than iron. According to the researchers, this was in some way a “random” discovery made during observations on VLT. With such a large force of gravity on these planets, they expected that such heavy elements would quickly fall into the lower layers of their atmospheres. However, after rechecking all the data, they are able to confirm that we are really talking about barium.

The night side of ultra-hot Jupiter in the artist’s image. Source: ESO/M. Kornmesser

The fact that barium was registered in the gas shells of both ultra-hot Jupiters indicates that this category of extrasolar worlds may be even stranger than previously thought. At the moment, scientists do not know what natural process can cause such a heavy element to appear at such high altitudes in the atmospheres of exoplanets. ​​

Recall that earlier we talked about the discovery of an old Jupiter-like exoplanet by the TESS telescope.

According to https://www.eso.org

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