About 212 light-years from Earth, a gas giant enough to be nicknamed the ‘super-bladder’ or ‘sugar-spider’ planet orbits it very close to its host. The exoplanet is so light, it makes astronomers question everything we previously knew about how gas giants originate.
This super-puff exoplanet, known as WASP-107b, is about the same size as Jupiter, but only about one-tenth the mass – or about 30 times more massive than Earth. According to a new study published in The Astronomical Journal on Monday, its core mass is significantly smaller than what astronomers considered necessary for the creation of a gas giant planet such as Jupiter and Saturn.
The discovery, made by Ph.D. student Caroline Piaulet under the supervision of Professor Björn Benneke at the University of Montreal, indicates that gas giants form much easier than previously believed.
“This study shifts the boundaries of our theoretical understanding of how giant-sized planets form. WASP-107b is one of the inflated planets out there, and we need a creative solution to explain how these tiny nuclei can form such massive gas envelopes. build, “co-author Eve Lee said in a statement.
WASP-107b is not a brand new discovery – astronomers first spotted it in the Virgo constellation in 2017. The planet is very close to its star, more than 16 times closer to the sun than the earth, and completes every 5, 7 days one orbit.
WASP-107b is one of the least dense exoplanets scientists have ever found. They are nicknamed similar types of planets – gas giants with the density of cotton candy – superpoffers.
ESA / HUBBLE, NASA, M. KORNMESSER
To find the surprising mass of the planet, astronomers studied observations obtained from the Keck Observatory in Hawaii. They use a technique called the radial velocity method, which studies the oscillating motion of a star from the planet by studying the gravity of a planet to calculate its mass.
Scientists were shocked to conclude that the solid core of WASP-107b has a mass no more than four times that of Earth, meaning that more than 85% of the mass from the thick gas layer around the core came. This is a dramatically different outline than Neptune, which has a similar mass but contains only 5% to 15% of it within its gas layer.
Based on their knowledge of Jupiter and Saturn, scientists previously believed that a solid core of at least ten times the Earth’s mass would be needed to obtain enough gas to form a gas giant planet. WASP-107b challenges the theory.
“This work addresses the foundation of how giant planets can form and grow,” Benneke said. “This provides concrete evidence that massive growth of a gas envelope can be caused by nuclear that is much less massive than previously thought.”
Lee claims that, “The most plausible scenario is that the planet formed far away from the star, where the gas in the disk is cold enough for gas growth to occur rapidly. The planet could later migrate to its current position, either through interactions with the disk or with other planets in the system. “
While studying the planet, they came across another in the same system, WASP-107c. It has a mass of about a third of Jupiter and takes three years to orbit its host once.
The planet’s oval orbit indicates that the astronomers’ new hypothesis is on track.
“WASP-107c has in some ways preserved the memory of what happened in its system,” Piaulet said. “Its great eccentricity points to a rather chaotic past, with interactions between the planets that could have led to significant shifts, such as those suspected of WASP-107b.”
The team hopes to continue studying the alien planet with the launch of the James Webb Space Telescope this year.