Super fluffy cotton-candy planet puzzles astronomers

Second least dense planet discovered 1,200 light years away

Web Desk
WASP-193b exoplanet discovered with cotton-candy-like atmosphere. — Nasa/JPL-Caltech

Researchers have stumbled on WASP-193b, a mind-boggling exoplanet with a density so low that they have nicknamed it cotton-candy planet as it looks like a huge fluffy gaseous mass hanging in space.

Despite being 50% bigger in size, the cotton-candy planet, located about 1,200 light years away from Earth, is seven times less dense than the gas giant Jupiter, according to a report published Monday in the journal Nature Astronomy.

The least dense planet ever discovered till the publication is Kepler-51d, which is considerably smaller than the recently discovered WASP-193b, Khalid Barkaoui, a study co-author and postdoctoral researcher at the University of Liège in Belgium, said in a statement, quoted by Popular Science.

"WASP-193b is the second least dense planet discovered to date, after Kepler-51d, which is much smaller," explains Barkaoui.

So far, according to Nasa, at least 5,000 exoplanets have been discovered — bodies that are outside our solar system.

Barkaoui said: "This extremely low density cannot be reproduced by standard models of irradiated gas giants, even under the unrealistic assumption of a coreless structure."

The planet was identified by the observatory called Wide Angle Search for Planets (WASP) located in Spain and South Africa.

Using the insights from the TRAPPIST-South and SPECULOOS-South observatories in Chile, astronomers measured signals from WASP-193b’s.

The results showed that WASP-193b has a very low density and its mass and size are about 0.14 and 1.5 that of Jupiter, meaning its density is about 0.059 grams per cubic centimeter.

Cotton candy’s density is 0.05 grams per cubic centimeter and Earth’s is 5.51 grams per cubic centimeter.

"The planet is so light that it’s difficult to think of an analogous, solid-state material," study co-author and Massachusetts Institute of Technology planetary scientist Julien de Wit said.

"The reason why it’s close to cotton candy is because both are pretty much air. The planet is basically super fluffy."

Researchers noted that WASP-193b is mostly made of hydrogen and helium.