The finding might cast doubt on our understanding of the formation of gas
giants like Jupiter.
An unique planetary system with a Jupiter-sized planet circling a tiny star
that is only four times the size of the gas giant in our solar system has
been found by astronomers. This "forbidden" arrangement of a large planet
circling a small star may cast doubt on ideas regarding the formation of gas
giant planets.
The "exoplanet," also known as an extrasolar planet, revolves around the
red dwarf star TOI 5205, which is much colder and smaller than the sun.
These M-dwarf stars, the most prevalent form of stellar entity in the Milky
Way, are smaller than the sun and have temps that are comparatively
cool.
Although this class of stars typically holds more planets than other star
types, it was originally thought that their formation makes it improbable
that gas giants will circle them. This exoplanet, TOI 5205b, was found by
scientists using NASA's Transiting Exoplanet Survey Satellite (TESS)
observatory, which casts doubt on that idea. With the aid of different
ground-based telescopes and instruments, the crew was able to corroborate
and describe the planet.
Team head and Carnegie Science astronomer Shubham Kanodia
said, "The host star, TOI-5205, is just about four times the size of Jupiter,
yet it has managed to create a Jupiter-sized planet, which is quite
amazing!"
Although gas giants have been found circling M dwarf stars in the past,
none of them have been found orbiting a TOI-5205 that is so low mass.
Protoplanetary discs, rotating spheres of gas and material that encircle
young stars, are where planets are born. Its center star was created when
the same material imploded, leaving behind this material. Planet centers are
created when dense regions fall due to their own gravity, at which point
they begin to gather more material.
According to current planet formation theories, it would require material
10 times the mass of Earth to give rise to a gas giant. This first creates a
rocky center, and from this core, a huge planet eventually develops by
accumulating gas. But this procedure must move swiftly.
"A gas giant planet cannot initially develop if there is not sufficient
rocky material in the disk to create the original nucleus. Finally, it is
impossible to create a gas giant planet if the disk evaporates away before
the huge center is created. Nevertheless, TOI-5205b developed despite these
barriers "Kanodia provided a statement explanation. "TOI-5205b should not
exist; it is a 'forbidden' planet," says the statement, "based on our
nominal present knowledge of planet creation."
Imagine our star, the sun, shrunk to the size of a grapefruit to get an
idea of how unbalanced this system is compared to the celestial systems that
scientists anticipate. Jupiter, the biggest gas giant in our solar system,
would be about the size of a garden pea after that size decrease.
A bean circling a lemon is more like the TOI-5205 system.
The size difference is so large that when TESS used the transit technique,
which measures the light loss brought on by planets passing in front of
their stars, the light loss was 7% of the star's overall light output.
The biggest known reduction in light produced by an extraterrestrial
transit, TOI-5205's dimming by this Jupiter-sized exoplanet.
Because of this sharp decrease in light, or formally, "large passage
depth," the system might be perfect for further research using the James
Webb Space Telescope (JWST).
The atmosphere of TOI-5205 b could be better understood and the processes
that gave rise to this "forbidden" planet's formation could be clarified
through observations made with the JWST.
The team's research is published in
The Astronomical Journal