Global Courant
Scientists have long been able to measure the chemicals in our own atmosphere with tremendous detail – but now, with the power of a very good telescope, astronomers are able to obtain the same detail for planets hundreds of light years away.
A new study by Canadian and international scientists has detailed the chemical composition for the atmosphere of a massive planet hurtling through space more than 634 light-years away from us.
The planet in question, called WASP-76 b, is a gas giant that orbits closely around a massive star in the constellation of Pisces. That’s according to a new study published Wednesday in the peer-reviewed journal Natureit orbits so close to its star that the planet itself can reach temperatures of up to 2,000 degrees Celsius.
“This is the first study to measure with high precision the amounts of chemical elements such as nickel, magnesium and chromium on a giant planet,” said Mohamad Ali-Dib, NYU Abu Dhabi Research Scientist at the Center for Astro, Particle, and Planetary Physics and one of the study’s authors, said in a press release.
WASP-76 b is not a newly discovered exoplanet, meaning a planet that orbits outside our solar system. It was first observed in 2013. However, this study offers a more in-depth look at what exactly constitutes this interstellar curiosity.
It’s not just a fun fact to know the chemicals that make up a planet’s atmosphere – they tell a story about the planet’s formation and significant past events.
In this case, researchers found chemicals in the atmosphere of WASP-76 b that are known to be rock-forming elements, not usually found in this amount in gas giants such as Jupiter and Saturn. The abundance of these rock-forming elements led researchers to hypothesize that WASP-76 b, which orbits its star on its lone orbit, may have once had a rocky neighbor orbiting it.
“The deviations of[the chemical]values from what is expected led us to hypothesize that WASP-76 b may have swallowed another much smaller planet, one with the same chemical composition as Mercury,” Ali-Dib said.
The study describes the amounts of a total of 11 chemical elements in the atmosphere.
Researchers also noted that the chemicals were constantly shifting in WASP-76 b’s upper atmosphere as temperatures changed.
As the planet orbits and moves around its star, different elements experience the temperature shifts that come with day and night — away from the star and toward it. They heat or cool depending on whether they are facing the star or not, which means a constant shift through the cycle of condensation: elements that form into a gas and go to the upper atmosphere, then liquefy and sink deeper into the planet’s atmosphere. lay as they cooled.
This shift from gas to liquid can be very abrupt for some elements, depending on their condensation temperature, researchers noted.
One of the exciting things about this research, which was conducted by an international team led by the Université de Montréal, is that ultra-hot gas giants such as WASP-76 b allow scientists to study elements in gas giants that are not close enough to the surface in the gas giants in our solar system to study.
WASP-76 b is about 12 times closer to its star than Mercury is to our sun. It is so hot on WASP-76 b that elements that could form rocks are only present in gaseous form, but they are in the upper atmosphere where we can study them. The same compounds can be found in a colder gas giant like Jupiter, but if they are, they’re in the lower atmosphere, closer to the center of the planet, where astronomers can’t yet detect them.
Researchers used data captured by the MAROON-X instrument on the Gemini-North telescope, which was designed to discover exoplanets and gather detailed information about their composition by analyzing light.
