Astronomers using the James Webb Space Telescope have revealed new details about the atmosphere of WASP-107b, an exoplanet nicknamed the "popcorn planet" because of its puffy nature. Recent findings reveal a surprising east-west asymmetry in its atmosphere, a feature never seen before, which sheds new light on the dynamic atmospheric conditions of this unique object.

Illustration of exoplanet WASP-107b orbiting its host star. This illustration is based on transit observations from NASA's James Webb Space Telescope's NIRCam instrument and other space-based and ground-based telescopes. Image credit: Rachel Amaro, University of Arizona

The charming "Popcorn Planet" is once again the center of attention! Using NASA's James Webb Space Telescope (JWST), an international team of astronomers has discovered new details about the atmosphere of WASP-107b, an exoplanet whose atmosphere expanded due to tidal heating. WASP-107b, previously described by researchers as an extremely low-density "popcorn planet," has once again proven to be a fascinating subject of study, with its expanded and vibrant atmosphere revealing more surprising features.

WASP-107b is a gas giant planet about the same size as Jupiter, but only one-tenth the mass. Now, JWST's advanced observing techniques have provided an even closer look, revealing unexpected east-west asymmetries in its atmosphere - the first time such details have been observed in an exoplanet.

"Our previous results showed that WASP-107b was unusually expanding, almost as if the planet was popping popcorn under its own heat," explained co-author Luis Welbanks, a 51Pegasib researcher in Arizona State University's School of Earth and Space Exploration. "With JWST, we can get a clearer understanding of the three-dimensional situation in its atmosphere. It turns out there is more to feast on!"

The research was published September 24 in the journal Nature Astronomy. The research was led by Matthew Murphy, a graduate student at the University of Arizona's Stewart Observatory, and also participated by Welbanks and associate professor Michael Line of Arizona State University.

New discovery highlights atmospheric asymmetry

Earlier in 2024, a previous study led by ASU researchers found that WASP-107b's internal temperature and core mass were significantly higher than previously assumed, thanks to broadband spectroscopy that simultaneously detected carbon, oxygen, nitrogen and sulfur molecules. Now, a reanalysis of JWST observations has discovered an east-west asymmetry in the atmosphere. This feature indicates differences in the properties of the two sides of the exoplanet.

"The origin of this asymmetry is curious. While our preliminary analysis suggests that this asymmetry may be due to one side of the planet being more cloudy than the other, it may also be related to the way heat is transported in the planet's atmosphere," Line said. "It's as if one side of WASP-107b is cooking faster than the other!"

WASP-107b is tidally locked to its star, meaning that one side of it always faces the star and is bathed in constant daylight, while the other side is permanently in darkness. This condition, combined with the planet's low gravity and expanded state, makes WASP-107b an ideal candidate for studying the unique processes at work in exoplanet atmospheres.

To study the planet's atmosphere, the researchers used a technique called transmission spectroscopy, which analyzes the starlight that passes through an exoplanet's atmosphere as it passes in front of its star. JWST's high sensitivity allowed the team to separate and examine signals from the eastern and western edges of the atmosphere separately, a level of detail never achieved before.

"The high precision of the JWST instrument is like equipping the planet with a magnifying glass," said Wellbanks. "We can now observe the specific processes occurring on each side of WASP-107b's atmosphere, providing valuable insights into how the climate operates under these extreme conditions."

Conclusion: Future Research and Implications

WASP-107b has an atmospheric temperature of about 890 degrees Fahrenheit, which is in the middle range between the solar system planets and the hottest known exoplanets. This makes it an important target for understanding the dynamics of different climates and atmospheres on exoplanets.

"Traditionally, our observational techniques haven't worked well for these medium-sized planets, so there are a lot of exciting open questions that we can finally start to answer," Murphy said. "For example, some of our models tell us that planets like WASP-107b shouldn't have this asymmetry at all -- so we're already learning new things."

The researchers now plan to conduct additional observations to delve deeper into the drivers of this atmospheric asymmetry. These ongoing studies will help astronomers piece together the puzzle of how this bulging exoplanet maintains its structure and how heat, winds and atmospheric chemistry interact to create the unique conditions observed on WASP-107b.

Compiled from/SciTechDaily