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Astronomers have discovered a planet whose density resembles a soft, porous marshmallow. We understand why it is of particular interest to scientists
How the marshmallow planet was discovered
A team of astronomers from around the world has discovered a giant gas planet orbiting a red dwarf star 580 light-years from Earth. The exoplanet (this term scientists refer to any planets outside the solar system), which was named TOI-3757 b, outwardly resembles Jupiter. It has the lowest density of all cosmic bodies ever observed in the orbit of red dwarfs – about 600 g / m3. This means that the exoplanet is similar in density to marshmallows. If it could be placed in a bath, it would float on water.
Features of red dwarfs
Red dwarfs are small and relatively cool stars that are quite common in our galaxy. They are usually small and dull. In their cores, they convert hydrogen into helium through nuclear fusion. Although these stars are much colder than the Sun, they are extremely active due to atomic reactions and release powerful bursts of gas that can destroy the atmosphere of any celestial body in their orbit. These outbursts theoretically make the cosmic neighborhood of red dwarfs an unlikely place to look for exoplanets. However, the presence of TOI-3757 b refutes this.
Giant dwarf satellite
TOI-3757 b is so close to its dwarf parent star that it takes just 3,5 Earth days to complete its orbit. This is 25 times faster than the closest planet to the Sun, Mercury, makes a complete revolution around it. At the same time, TOI-3757 b is slightly larger than Jupiter, the largest planet in the solar system, with a diameter of about 150 thousand km. Shubham Canodia, lead author of the study and astronomer at the Carnegie Institution in Washington, said TOI-3757 b is an exception to the rule that giant planets rarely form around red dwarfs.
Why did the anomaly appear?
Kanodia and his colleagues are confident that the formation of a low-density gas giant in such adverse and extreme conditions is an amazing phenomenon. They suggest that two factors made it possible.
delayed formation
The first factor has to do with how gas giants form. Massive rocky cores, about ten times the mass of the Earth, quickly draw in a large amount of the surrounding gas and turn into planets like Jupiter. The team of scientists believe that the red dwarf that TOI-3757 b orbits contained fewer heavy elements. This led to the fact that due to complex chemical reactions, the core of the exoplanet was formed more slowly. This delayed the addition of gas, which made the planet less dense.
Dangerous Approaches
The second factor is that the orbit of TOI-3757 b has the shape of an ellipse, so periodically the planet is as close as possible to its parent star. Such approaches lead to excessive heating of the planet, which causes its atmosphere to swell – due to the heat, gas is ejected into it.