AN ACCIDENTAL DISCOVERY OF BARIUM IN THE ATMOSPHERE OF AN EXOPLANET
Recently, astronomers studied, the WASP-76 and WASP-121b and found the heaviest element- Barium, ever discovered in any exoplanet’s atmosphere.
The High-Resolution Spectroscopy of extrasolar planets is one of the keys to our understanding of the Exoplanet atmospheres. This method helps us in understanding the formation, environment and evolution of the planets, as we explore the data of their compositions and physical dynamics, an overall advancement in exoplanetary research studies.
Recently, astronomers studied, the WASP-76 and WASP-121b and found the heaviest element- Barium, ever discovered in any exoplanet’s atmosphere. These planets do fall in the class of gas giant exoplanets, commonly known as “Hot Jupiters”, a type of planet that is similar to Jupiter but they have a very shorter orbital period, of around less than 240 hours (P<10 days), this close proximity to their stars, establishes a very hotter surface atmospheric temperatures, regarding them as “Hot Jupiters”.
Using the data from, VLT and ESPRESSO, the scientist took a new look at the two exceptionally ultra-hot Jupiters, and they reassessed the transit observations to attempt to find any new species in the atmosphere of the planets.
Excitingly and accidentally, scientists added the discovery of Ba+ present in the atmospheric composition of the WASP-76b and WASP-121b, and also the new detections of Co and Sr+. The results also made confirmations for the previously detected elements such as Ca+, Cr, Fe, H, Li, Mg, Mn, Na and V on both planets.
Reporting and referring from different science news outlets, Azevedo Silva – the lead study author (Doctoral student at the University of Porto) said, “This was in a way ‘accidental’ discovery – we just wanted to confirm we already knew everything that was there. We were not looking barium, and I don’t think anyone was looking barium, because there is no reason for the barium to be there”.
“It’s very puzzling and counterintuitive: why s there such a heavy element in the upper layers of the atmosphere of these planets?”
Considering, “Barium” is much heavier than most elements, we expect to find it high up in a planetary atmosphere- it is approximately 2.5 times as heavy as iron. “Our thought is that something so heavy would sink down the atmosphere,” says Azevedo Silva. “This raises a lot of questions about how it got there and what’s going on. ” – Reported in NewScientist
Both planets are similar to Jupiter in size, but they have incredibly hot surface temperatures, above 1,832 degrees Fahrenheit (1,000 degrees Celcius), and they both are located so close to their host stars that their orbital period is about one or two days.
Later in future, astronomers can discover more through Higher Resolution Spectrography, through instruments under development such as ANDES on ELT in Chile, which can also study not only the large planets but smaller rocky worlds like earth.
For reference, a paper elaborating on the work and methods above was published on Oct 13, 2022, in the journal Astronomy & Astrophysics.
Also, read: Exoplanets: The Possible Aliens’ World
I am a Writer and Science Communicator at Scientia Magazine, who also lectures and audits – Aviation/Aeronautical Engineering at ATH – IST. My interests in studies are Aviation, Data-Driven Astronomy/Astrophysics, Environment, and other Space Sciences.