All planets are round, but they are not all perfectly symmetrical. Thanks to the James Webb Space Telescope, scientists have captured the first images of a planet in outer space with asymmetric edges in its atmosphere. Moreover, this stunning contrast takes place on an exoplanet where one side permanently faces its sun.
Published in the journal Nature Astronomy, scientists from the University of Arizona say this east-west asymmetry means there are differences in atmospheric conditions between the two hemispheres of this strange new world. According to the authors, the asymmetry results from the position of the exoplanet in relation to the star it orbits.
Study authors explain that the planet is “tidally locked” — meaning the same side always faces the star and other side stays in darkness. The differences in gases, temperature, and cloud patterns for each side give scientists a unique opportunity to study how planets change when they get different amounts of sunlight.
“This is the first time the east-west asymmetry of any exoplanet has ever been observed as it transits its star, from space,” says lead study author Matthew Murphy, a graduate student at the University of Arizona’s Steward Observatory, in a media release.
Transit refers to a planet moving in front of its sun, allowing astronomers here on Earth to see these disruptions and learn more about the planets orbiting distant stars.
“We don’t have anything like it in our own solar system. It is unique, even among the exoplanet population,” Murphy adds.
Exoplanet WASP-107b is roughly the same size as Jupiter, but it only carries about a tenth of the mass. This low level of density and low amount of gravity makes the atmosphere more inflated than other exoplanets, contributing to its massive size. WASP-107b is estimated to be around 890 degrees Fahrenheit — a temperature that falls in between planets of our solar system and the hottest known exoplanets.
“Traditionally, our observing techniques don’t work as well for these intermediate planets, so there’s been a lot of exciting open questions that we can finally start to answer,” explains Murphy. “For example, some of our models told us that a planet like WASP-107b shouldn’t have this asymmetry at all — so we’re already learning something new.”
Planets outside our solar system have been a topic of interest to the researchers for almost two decades. Images and observations from ground and space have helped in predicting the atmosphere of exoplanets.
“But this is really the first time that we’ve seen these types of asymmetries directly in the form of transmission spectroscopy from space, which is the primary way in which we understand what exoplanet atmospheres are made of — it’s actually amazing,” says study co-author Thomas Beatty, an assistant professor of astronomy at the University of Wisconsin-Madison.
The next step is to use the observational data to get a more detailed view of the exoplanet and what drives this unique asymmetry.
“For almost all exoplanets, we can’t even look at them directly, let alone be able to know what’s going on one side versus the other,” Murphy concludes. “For the first time, we’re able to take a much more localized view of what’s going on in an exoplanet’s atmosphere.”
Source: https://studyfinds.org/inflated-asymmetrical-planet/?nab=0