the sciences. – Giant planets’ atmospheres vary widely – Publimetro México

Madrid, 28 (Europe Press)

In our system, the greater the mass of the planet, the lower the percentage of “heavy” elements (anything other than hydrogen and helium) in the planet’s atmosphere. An international team of astronomers in the galaxy has discovered that the atmosphere compositions of the giant planets do not match the orientation of the solar system.

Using the James Webb Space Telescope (JWST), researchers have found that the atmosphere of exoplanet HD149026b, a “hot Jupiter” orbiting a star similar to our Sun, is extremely abundant in the heavy elements carbon and oxygen, much higher than scientists thought. It is considered. We expect a planet with its mass. Furthermore, the diagnostic carbon to oxygen ratio of HD149026b, also known as “Smertrios”, is high relative to our solar system.

The findings, published in the journal Nature, are an important first step in obtaining similar measurements of a large sample of exoplanets in order to look for statistical trends, according to the new research. They also provide information about the formation of planets.

“It seems that every giant planet is different, and we’re starting to see these differences thanks to JWST,” said Jonathan Lunin, professor of physical sciences at Cornell University and co-author of the study. “In this paper, we have determined how many molecules there are in relation to the main component of the gas, which is hydrogen, which is the most common element in the universe. That tells us a lot about how this planet formed.”

The giant planets in our solar system show an almost perfect correlation between overall composition, atmospheric composition, and mass, Jacob Bean, professor of astronomy and astrophysics at the University of Chicago and lead author of the paper, said in a statement. Exoplanets show a much greater diversity of overall compositions, but scientists didn’t know just how diverse their atmosphere compositions were until HD149026b’s analysis.

“We have shown definitively that the atmospheric formations of exoplanets do not follow the same apparent orientation as planets in the solar system,” Bean said. “The giant exoplanets show a great diversity of atmospheric compositions in addition to their wide diversity in overall compositions.”

Smertrios, for example, is super-fertile compared to its mass, Lunin said. “It is the mass of Saturn, but its atmosphere appears to contain up to 27 times the amount of the heavy elements relative to the hydrogen and helium that we find on Saturn.”

This ratio, which is called “metallic” (although it includes many elements that are not metals), Lunin said, is useful for comparing a planet to its parent star or to other planets in its system. Smertrios is the only known planet in this particular planetary system.

Another key measurement, Lunin said, is the ratio of carbon to oxygen in a planet’s atmosphere, which reveals the “recipe” for the original solids in a planetary system. For Smertrios, it is about 0.84 orders of magnitude higher than in our solar system. In our sun, it is just over one carbon for every two oxygen atoms (0.55).

“Together, these observations paint a picture of a planet-forming disk abundant in carbon-rich solids,” Lunin said. “HD149026b acquired large amounts of this material when it formed.”

While an abundance of carbon may seem favorable to the chances of life, a higher carbon-to-oxygen ratio actually means less water on a planet or in a planetary system, which is a problem for life as we know it.

Smertrios is an interesting first case of atmospheric composition for this particular study, said Lunine, who has plans to observe five more giant exoplanets next year using JWST. Many additional observations are needed before astronomers can detect the patterns among giant planets or in systems with multiple giant planets or terrestrial planets of the compositional diversity astronomers have begun to document.

“The origin of this diversity is a fundamental puzzle in our understanding of planetary formation,” Bean said. “We hope that further observations of exoplanet atmospheres using the JWST will better define this diversity and bring constraints to the more complex trends that may be present.”