Scientists at Lund University in Sweden have found the rare metal terbium in the atmosphere of an exoplanet for the first time in a ground-breaking discovery. An exoplanet is one that orbits a star outside the solar system.
The breakthrough is the result of a new method of analyzing exoplanets, also known as extrasolar planets, which allows for more detailed study than ever before.
The exoplanet in question is KELT-9 b, the hottest exoplanet known to humanity. This planet orbits a distant star about 670 light years away from Earth and boasts an average temperature of an astonishing 4,000 degrees Celsius.
"Using this, we have discovered seven elements, including the rare substance terbium, which has never before been found in any exoplanet's atmosphere."
PhD student in astrophysics at Lund University, Nicholas Borsato
Since its discovery in 2016, KELT-9b has captured the attention of astronomers worldwide and this latest peer-reviewed study, published in Astronomy & Astrophysics on April 13, promises to shed new light on its unique atmosphere.
The discovery of terbium in KELT-9b's atmosphere is significant because it suggests that the planet's atmosphere contains a unique mix of elements that are unlike anything found in our own solar system. This, in turn, could provide valuable clues about how exoplanets form and evolve over time.
"We have developed a new method that makes it possible to obtain more detailed information," PhD student in astrophysics at Lund University, Nicholas Borsato said. "Using this, we have discovered seven elements, including the rare substance terbium, which has never before been found in any exoplanet's atmosphere."
What is terbium? What makes it so special?
Terbium, a rare earth metal belonging to the lanthanoid group, was first discovered in 1843 by the Swedish chemist Carl Gustaf Mosander in the Ytterby mine located in the Stockholm archipelago.
With its scarcity in nature, it remains a highly sought-after substance to this day, with 99% of the world's terbium production being carried out in the Bayan Obo mining district situated in Inner Mongolia.
"Finding terbium in an exoplanet's atmosphere is very surprising," Borsato said.
Astronomers have traditionally discovered exoplanets by measuring the brightness of stars. However, with advancements in measurement methods, researchers have developed a new technique to filter out dominant signals in the atmosphere of KELT-9 b, one of the hottest exoplanets known to humanity.
By removing these dominant signals, the researchers have gained a more detailed understanding of the unique atmosphere of KELT-9 b. This breakthrough opens up exciting possibilities for future research into the atmospheres of other exoplanets, providing a potential gateway to a greater understanding of these distant worlds.
In 1992, the discovery of an exoplanet orbiting a neutron star marked a significant breakthrough in the field of astronomy. Three years later, the first exoplanet with a sun-like star was confirmed.
Since then, over 5,000 exoplanets have been recorded, unveiling the vastness of the universe beyond our solar system. While some exoplanets have been deemed potentially habitable, the search for extra-terrestrial life remains a fascinating area of research.
"The better we get to know these planets, the greater chance we have of finding Earth 2.0 in the future," Borsato said.