Researchers find 2 giant planets with density lighter than cotton candy

Light planets: An illustration of the giant planets TOI-791 b and TOI-791 c with host star TOI-791. These planets are roughly the size of Jupiter, but have a tiny fraction of its mass (NASA/Daniel Rutter.)

The latest celestial buzz is light-years away from Earth.

Researchers led by a team from the University of Oxford have uncovered two “super-puff” planets larger than Jupiter but with density levels lighter than cotton candy.

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The discovery was published on Wednesday in Monthly Notices of the Royal Astronomical Society.

The two lightweights -- named TOI-791 b and TOI-791 c -- orbit a dwarf star 1,110 light-years away from Earth, the Society wrote.

The F7-type star is located in the southern constellation Volan.

The study was a collaboration between the University of Oxford, Université Côte d’Azur/Observatoire de la Côte d’Azur and the University of Birmingham, the Society said.

TOI-791 b has a density of just 0.038 grams per cubic centimeter, while TOI-791 c has a density of 0.047 grams per cubic centimeter. By comparison, Earth’s density is 5.5 grams per centimeter, while cotton candy is at 0.05 grams, researchers said.

That makes them the lightest known planets of their size, according to the University of Oxford’s George Dransfield.

“These two planets have densities comparable to a nice blob of shaving foam, fresh from the can,” Dransfield told The Associated Press in an email.

Researchers called the planets “siblings” and believe they formed together from the same disc of gas and dust surrounding the star they orbit.

Only four other systems are known to contain multiple super-puff planets, researchers said.

“Only a handful of these super-puffy planets are known, and it is even rarer to find two in the same system,” Dransfield said in the study. “Their extremely low densities make them fascinating targets for understanding how planetary systems form and evolve.”

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