Astronomers have discovered a single “super blown” planet as large as Jupiter, but ten times lighter.
The planet, called WASP-107b, is believed to be one of the least dense exoplanets ever discovered, giving it the nickname of a “super-puff” or “candy cotton” planet.
Researchers say the findings have “big implications” for what we understand about how giant planets form and grow.
WASP-107b is very close to its star, WASP-107, with estimates suggesting that the planet is more than 16 times its star than Earth in the Sun.
WASP-107b is about 212 light-years from Earth, in the constellation Virgo.
Estimates suggest that the planet is more than 16 times closer to its star, WASP-107, than Earth to the Sun.
Through observations obtained by the Keck Observatory in Hawaii, researchers at the University of Montreal have been able to determine the size and density of the planet.
Their results suggest that the WASP-107b is about the same size as Jupiter, but is about ten times lighter.
This extremely low density indicates that the planet must have a solid core no more than four times the mass of Earth, according to researchers.
This suggests that more than 85% of its mass lies in the thick layer of gas that surrounds its core.
Caroline Piaulet, a doctoral student at the University of Montreal and lead author of the study, said: “We had a lot of questions about WASP-107b. How could a planet of such low density be formed?
“And how did it prevent its huge layer of gas from escaping, especially given the planet’s proximity to its star?”
“This motivated us to do a thorough analysis to determine their training history.”
Most gas giant planets, such as Jupiter and Saturn, have a solid core at least 10 times more massive than Earth.
Estimates suggest that the planet is about the same size as Jupiter, but is about ten times lighter.
However, the WASP-107b has a much less massive core, which led researchers to question how the planet was able to exceed the critical threshold needed to accumulate and retain its gas envelope.
Professor Eve Lee, a world-renowned expert on super-puff planets, has several theories.
“For WASP-107b, 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 accretion to occur very quickly,” he said.
“The planet was later able to migrate to its current position, either through interactions with the disk or with other planets in the system.”
Surprisingly, previous data from NASA’s Hubble spacecraft suggest that WASP-107b contains very little methane.
Piaulet said: “It’s strange, because for this type of planet methane should be abundant. We are now reanalyzing Hubble’s observations with the new mass of the planet to see how it will affect the results and examine what mechanisms could explain the destruction of the planet. half “.
The WASP-107b is about the same size as Jupiter (pictured), but is ten times lighter than the gas giant.
Observations also revealed that WASP-107b is not alone in the orbit of the star WASP-107, but binds to another planet, called WASP-107c.
The WASP-107c has a mass of about one-third that of Jupiter and is much farther from its central star than the WASP-107b, taking three years to complete an orbit, compared to just 5.7 days.
Interestingly, the eccentricity of this second planet is high, meaning its trajectory is more oval than circular.
Piaulet explained: “The WASP-107c has kept in some respects the memory of what happened to its system.
“Its great eccentricity hints at a rather chaotic past, with interactions between planets that could have caused significant displacements, such as the WASP-107b suspect.”
The team hopes the findings shed light on the different mechanisms of planet formation throughout the universe.
Piaulet added: “Exoplanets like WASP-107b that have no analogy in our solar system allow us to better understand the mechanisms of planet formation in general and the resulting variety of exoplanets. It motivates us to study them in every detail ”.
Scientists study the atmosphere of distant exoplanets using huge space satellites like Hubble
Distant stars and their orbiting planets often have different conditions than anything we see in our atmosphere.
To understand this new world and what they are made of, scientists must be able to detect what their atmospheres consist of.
They often do so using a telescope similar to NASA’s Hubble Telescope.
These huge satellites explore the sky and look at exoplanets that NASA believes may be of interest.
Here, the sensors on board perform different forms of analysis.
One of the most important and useful is called absorption spectroscopy.
This form of analysis measures the light that comes out of a planet’s atmosphere.
All gases absorb a slightly different wavelength, and when this happens, a black line appears in a full spectrum.
These lines correspond to a very specific molecule, which indicates their presence on the planet.
Fraunhofer lines are often named after the German astronomer and physicist who discovered them in 1814.
By combining all the different wavelengths of lights, scientists can determine all the chemicals that make up a planet’s atmosphere.
The key is that what is missing, provides clues to find out what is present.
It is vitally important that this is done using space telescopes, as the Earth’s atmosphere would interfere.
The absorption of chemicals into our atmosphere would skew the sample, so it is important to study light before it has had a chance to reach Earth.
It is often used to search for helium, sodium and even oxygen in alien atmospheres.
This diagram shows how light passing from a star and passing through the atmosphere of an exoplanet produces Fraunhofer lines that indicate the presence of key compounds such as sodium or helium.