Astronomers report two newly confirmed “super-puff” exoplanets, TOI-791 b and TOI-791 c, that are about the size of Jupiter but have extremely low densities—described across outlets as less dense than cotton candy, candy floss, or shaving foam. The planets orbit the same distant star in the southern constellation Volans (the flying fish) at a distance of about 1,110 light-years from Earth. Because the worlds are so diffuse, scientists say they contain very little mass for their size, implying large, lightweight atmospheres and rare physical conditions.
The research combines data from NASA’s TESS mission, which detected the planets, with follow-up observations from Earth-based telescopes. Those observations help determine the planets’ orbital characteristics, which in turn allow researchers to estimate their density. Sources also describe the two planets as being in a gravitationally interacting configuration that affects their orbits.
Scientists say super-puffs are uncommon and may form and evolve under specific circumstances in the gas-and-dust disks around young stars, potentially losing substantial material over time. Further study is expected, including using the James Webb Space Telescope to probe atmospheric composition.
