Two Jupiter-sized Planets Found, But Lighter Than Cotton Candy 0 14

Astronomers from the United Kingdom have identified a pair of giant planets outside the Solar System that are Jupiter-sized. They orbit the star TOI-791 and are called TOI-791 b and TOI-791 c. Despite their size, these celestial bodies have the lowest density of all discovered, as noted in a study published in the Monthly Notices of the Royal Astronomical Society.

The scientists used the Transit Timing Variation (TTV) method, which analyzes changes in the time it takes for a planet to pass in front of the star's disk. This allowed researchers to calculate the mass of the celestial bodies. TOI-791 b is nearly the same size as Jupiter, but its weight is only 3% of Jupiter's mass, while the larger TOI-791 is just 5.9%.

"The density is extremely low and comparable to the density of gas giants from the Kepler-51 system. The mass constraints and upper mass limits obtained in this work are reliable for the existing dataset," the study results state.

Super-puffs, or loosely defined gas giants, refer to celestial bodies with enormous sizes and very sparse structures. Measurements at the star TOI-791 were conducted using NASA's Transiting Exoplanet Survey Satellite (TESS) during its mission.

According to the American space agency, the celestial bodies are located about 1,113 light-years from Earth, and their density "is comparable to cotton candy." Currently, science knows only a few such planets, and even more rarely can two similar celestial objects be found within the same star system, notes lead author George Dansfield from the University of Oxford's Department of Physics.

The low density makes such celestial objects interesting for studying the formation and evolution of planetary systems as a whole, the scientist adds. John Jenkins, the scientific director of the Scientific Data Processing Center at NASA's Ames Research Center in Silicon Valley, California, shares a similar view.

"The main reason these planets are so interesting to study is that we did not expect to find them at all. They represent a puzzle that we need to solve to understand how giant planets like Jupiter and super-puffs form," Jenkins emphasizes.

Researchers note that theoretical models describing the formation and subsequent migration of celestial bodies predict different outcomes regarding the mass of the planets and their eccentricity, which indicates how much their orbit resembles a perfect circle or an elongated oval. All of this allows for the study of the origins of celestial objects.

The emergence of such celestial bodies in space is a "relatively rare outcome of the planet formation process," the scientists emphasize. Key questions about the nature and creation of this subgroup of super-puffs remain unanswered, necessitating further research.