Researchers spot clouds in the atmosphere of big, puffy exoplanet WASP-127b

By Georgina Torbet September 26, 2021

Researchers have made a rare detection of clouds in the atmosphere of an exoplanet, spotting puffs of unknown composition floating above the fluffy, puffy planet WASP-127b.

Planet WASP-127b was in the news in 2018 when researchers from the Instituto de Astrofísica de Canarias (IAC) discovered it was one of the least dense exoplanets ever found and was unlike anything in our solar system.

This is an artistic simulation of WASP 127b orbiting a star. — This is an artistic simulation of WASP 127b orbiting a star. Gabriel Pérez, SMM (IAC)

The planet is a great candidate for researching exoplanet atmospheres because it is so large and “fluffy.” It is 1.3 times larger than Jupiter, but just one-fifth of its mass. And because it orbits very close to its host star, a year there lasts just four days and its surface temperature rises up to 1100 degrees Celsius. That makes it a type of planet called a “hot Saturn.”

Now, researchers have used data from the Hubble Space Telescope along with a spectroscopy instrument — the Echelle SPectrograph for Rocky Exoplanets and Stable Spectroscopic Observations (ESPRESSO) at the European Southern Observatory’s Very Large Telescope in Chile — to identify clouds that are floating in the planet’s atmosphere. They also found sodium in the atmosphere, but at a lower altitude than was expected.

“We don’t yet know the composition of the clouds, except that they are not composed of water droplets like on Earth,” said lead author Romain Allart. “We are also puzzled about why the sodium is found in an unexpected place on this planet. Future studies will help us understand not only more about the atmospheric structure but about WASP-127b, which is proving to be a fascinating place.”

There are even more oddities to WASP-127b though. Not only does it orbit in the opposite direction to its star, but it also orbits in an unusual plane rather than the typical equatorial plane.

“Such alignment is unexpected for a hot Saturn in an old stellar system and might be caused by an unknown companion,” said Allart. “All these unique characteristics make WASP-127b a planet that will be very intensely studied in the future.”

The research is published in the journal Astronomy & Astrophysics.

Editors' Recommendations

Topics

Georgina Torbet

Space Writer

Georgina is the Digital Trends space writer, covering human space exploration, planetary science, and cosmology. She…

Space

James Webb investigates a super puffy exoplanet where it rains sand

$Artistic concept of the exoplanet WASP-107b and its parent star. Even though the rather cool host star emits a relatively small fraction of high-energy photons, they can reach deep into the planet’s fluffy atmosphere.$

Exoplanets come in many forms, from dense, rocky planets like Earth and Mars to gas giants like Jupiter and Saturn. But some planets discovered outside our solar system are even less dense than gas giants and are a type known informally as super-puff or cotton candy planets. One of the least dense exoplanets known, WASP-107b, was recently investigated using the James Webb Space Telescope (JWST) and the planet's weather seems to be as strange as its puffiness.

The planet is more atmosphere than core, with a fluffy atmosphere in which Webb spotted water vapor and sulfur dioxide. Strangest of all, Webb also saw silicate sand clouds, suggesting that it would rain sand between the upper and lower layers of the atmosphere. The planet is almost as big as Jupiter but has a tiny mass similar to that of Neptune.

Space

Hubble spots an Earth-sized exoplanet just 22 light-years away

An artist’s concept of the nearby exoplanet, LTT 1445Ac, which is the size of Earth. The planet orbits a red dwarf star.

Although astronomers have now discovered more than 5,000 exoplanets, or planets outside of the solar system, the large majority of these planets are considerably larger than Earth. That's partly because it's easier to spot larger planets from tremendous distances across space. So it's exciting when an Earth-sized planet is discovered -- and the Hubble Space Telescope has recently confirmed that a nearby planet, which is diminutive by exoplanet standards, is 1.07 times the size of Earth.

The planet LTT 1445Ac was first discovered by NASA's Transiting Exoplanet Survey Satellite (TESS) in 2022, but it was hard to determine its exact size due to the plane of its orbit around its star as seen from Earth. “There was a chance that this system has an unlucky geometry and if that’s the case, we wouldn’t measure the right size. But with Hubble’s capabilities we nailed its diameter,” said lead researcher Emily Pass of the Harvard-Smithsonian Center for Astrophysics in a statement.

Space

James Webb sees evidence of an ocean-covered ‘Hycean’ exoplanet

This illustration shows what exoplanet K2-18 b could look like based on science data. K2-18 b, an exoplanet 8.6 times as massive as Earth, orbits the cool dwarf star K2-18 in the habitable zone and lies 120 light years from Earth.

The James Webb Space Telescope has once again peered into the atmosphere of an exoplanet, and this time it has identified indications that the planet could be covered in oceans. The planet K2-18 b is just 120 light-years away from Earth in the constellation of Leo and is a type of planet called a sub-Neptune which is unlike any planet in our solar system.

Researchers used Webb to investigate K2-18 b, which is more than eight times the mass of Earth and orbits a small, cool dwarf star. It is located within the habitable zone of the star, where it is possible for water to exist on the planet's surface, and the data suggests that this could be an ocean world.