At about 212 light-years from Earth, a giant gas light large enough to be nicknamed a “super-fluffy” or “sugarcane” planet revolves extremely close to its host star. exoplanet it’s so easy that astronomers have questioned everything we previously knew about how gas giants form.
This super fluff exoplanet, known as WASP-107b, is about the same size as Jupiter, but only about a tenth of the mass – or about 30 times more massive than Earth. According to a new study published Monday in The Astronomical Journal, its base mass is significantly smaller than astronomers thought it was needed to create a giant gas planet like Jupiter and Saturn.
The discovery, made by Dr. Caroline Piaulet under the supervision of Professor Björn Benneke of the University of Montreal, indicates that gas giants form much more easily than previously thought.
“This study exceeds the limits of our theoretical understanding of how giant planets form. WASP-107b is one of the most inflated planets out there, and we need a creative solution to explain how these small nuclei can build such massive gas envelopes, “co-author Eve Lee said in a statement.
WASP-107b is not a completely new discovery – astronomers first detected it in the constellation Virgo in 2017. The planet is very close to its star, more than 16 times closer to the Sun Earth, completing one orbit every 5 ,7 days.
WASP-107b is one of the least dense exoplanets scientists have ever found. They nicknamed similar types of planets – gas giants with a density of cotton wool – super fluff.
ESA / HUBBLE, NASA, M. KORNMESSER
To find the planet’s surprising mass, astronomers studied observations at the Keck Observatory in Hawaii. They used a technique called the radial velocity method, which studies the oscillating motion of a planet’s star caused by a planet’s gravitational attraction to calculate mass.
Scientists have been shocked to conclude that the solid core of WASP-107b has a mass no more than four times that of Earth, which means that more than 85% of its mass comes from the thick gaseous layer that surrounds the core. This is a dramatically different breakdown from Neptune, which has a similar mass, but holds only 5% to 15% of it in its gas layer.
Based on their knowledge of Jupiter and Saturn, scientists previously believed that it would take a solid core at least 10 times the mass of Earth to gain enough gas to form a giant gas planet. WASP-107b challenges this theory.
“This paper addresses the very basics of how giant planets can form and grow,” Benneke said. “It provides concrete evidence that the massive accretion of a gas tire can be triggered for nuclei that are much less massive than previously thought.”
Lee claims that “the most plausible scenario is that the planet formed far from the star, where the gas in the disk is cold enough for the gas accretion to take place very quickly. The planet was later able to migrate to its current position, either through interactions with the disk or other planets in the system. “
While studying the planet, the team came across another in the same system, WASP-107c. It has a mass that is about a third of that of Jupiter and takes three years to orbit with the host star.
The oval orbit of the planet suggests that astronomers’ new hypothesis is on track.
“WASP-107c has kept, in some respects, the memory of what happened in its system,” Piaulet said. “Its great eccentricity suggests a rather chaotic past, with interactions between planets that could have led to significant displacements, such as the one suspected for WASP-107b.”
The team hopes to continue studying the strange planet once it launches James Webb Space Telescope this year.