Topic: Space

Astronomers have discovered two giant planets that are incredibly light and fluffy. They orbit a small star about 1,110 light-years from Earth.

A team of astronomers has found two rare 'super-puff' planets that are much lighter than cotton candy. These planets are huge, but they're surprisingly lightweight. TOI-791 b is about the size of Jupiter, but it's only as dense as a feather. TOI-791 c is also massive, but it's even less dense than its sibling planet.

The two planets orbit an F7-type dwarf star in the southern constellation Volans. They're part of a rare system where both planets are super-puff and have very low densities. This makes them fascinating targets for understanding how planetary systems form and evolve.

The discovery was made possible by eight years of observations from telescopes around the world, including data from the ASTEP telescope at Concordia Station in Antarctica. The long winter nights in Antarctica allowed astronomers to observe the planets' unusually long transits without interruption.

Scientists believe that the two planets formed together from the same disc of gas and dust surrounding their young star. They're also linked by an unusual orbital arrangement called a 5:3 mean-motion resonance. This means that for every five orbits completed by the inner planet, the outer planet finishes almost exactly three. As they circle their star, their gravity repeatedly pulls on one another, creating small but measurable changes in the timing of each planet's transit.

The discovery was built on eight years of observations and data from telescopes around the world. The findings were published in Monthly Notices of the Royal Astronomical Society.

Why It Matters

This discovery helps us understand how planetary systems form and evolve, which is important for understanding our own solar system and the possibility of life beyond Earth.

Key Facts

• Two super-puff planets, TOI-791 b and TOI-791 c, were found orbiting an F7-type dwarf star about 1,110 light-years from Earth.
• The two planets are huge but incredibly lightweight, with densities lower than cotton candy.
• The discovery was made possible by eight years of observations from telescopes around the world, including data from the ASTEP telescope at Concordia Station in Antarctica.
• The two planets formed together from the same disc of gas and dust surrounding their young star.
• Their unusual orbital arrangement is a 5:3 mean-motion resonance.

Key Terms

Super-puff planet

A giant planet that is much lighter than expected, with a density lower than cotton candy.

Implications

This discovery helps us understand how planetary systems form and evolve, which is important for understanding our own solar system and the possibility of life beyond Earth.